backout: provide linear backout as a default (without --merge option)

This changes backouts changeset to retain linear history, .e. it is committed
as a child of the working directory parent, not the reverted changeset
parent.

The default behavior was previously to just commit a reverted change as a
child of the backed out changeset - thus creating a new head. Most of
the time, you would use the --merge option, as it does not make sense to
keep this dangling head as is.
The previous behavior could be obtained by using 'hg update --clean .' after a
'hg backout --merge'.

The --merge option itself is not affected by this change. There is also
still an autocommit of the backout if a merge is not needed, i.e. in case
the backout is the parent of the working directory.

Previously we had (pwd = parent of the working directory):
                  pwd     older
backout           auto    merge
backout --merge   auto    commit

With the new linear approach:
                  pwd     older
backout           auto    commit
backout --merge   auto    commit

auto: commit done by the backout command
merge: backout also already committed but explicit merge and commit needed
commit: user need to commit the update/merge

mercurial/commands.py

@@ -1,4453 +1,4460 b''
 # commands.py - command processing for mercurial
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from node import hex, nullid, nullrev, short
 from lock import release
 from i18n import _, gettext
 import os, re, sys, difflib, time, tempfile
 import hg, util, revlog, extensions, copies, error
 import patch, help, mdiff, url, encoding, templatekw, discovery
 import archival, changegroup, cmdutil, sshserver, hbisect, hgweb, hgweb.server
 import merge as mergemod
 import minirst, revset
 import dagparser
 
 # Commands start here, listed alphabetically
 
 def add(ui, repo, *pats, **opts):
     """add the specified files on the next commit
 
     Schedule files to be version controlled and added to the
     repository.
 
     The files will be added to the repository at the next commit. To
     undo an add before that, see :hg:`forget`.
 
     If no names are given, add all files to the repository.
 
     .. container:: verbose
 
        An example showing how new (unknown) files are added
        automatically by :hg:`add`::
 
          $ ls
          foo.c
          $ hg status
          ? foo.c
          $ hg add
          adding foo.c
          $ hg status
          A foo.c
 
     Returns 0 if all files are successfully added.
     """
 
     m = cmdutil.match(repo, pats, opts)
     rejected = cmdutil.add(ui, repo, m, opts.get('dry_run'),
                            opts.get('subrepos'), prefix="")
     return rejected and 1 or 0
 
 def addremove(ui, repo, *pats, **opts):
     """add all new files, delete all missing files
 
     Add all new files and remove all missing files from the
     repository.
 
     New files are ignored if they match any of the patterns in
     .hgignore. As with add, these changes take effect at the next
     commit.
 
     Use the -s/--similarity option to detect renamed files. With a
     parameter greater than 0, this compares every removed file with
     every added file and records those similar enough as renames. This
     option takes a percentage between 0 (disabled) and 100 (files must
     be identical) as its parameter. Detecting renamed files this way
     can be expensive. After using this option, :hg:`status -C` can be
     used to check which files were identified as moved or renamed.
 
     Returns 0 if all files are successfully added.
     """
     try:
         sim = float(opts.get('similarity') or 100)
     except ValueError:
         raise util.Abort(_('similarity must be a number'))
     if sim < 0 or sim > 100:
         raise util.Abort(_('similarity must be between 0 and 100'))
     return cmdutil.addremove(repo, pats, opts, similarity=sim / 100.0)
 
 def annotate(ui, repo, *pats, **opts):
     """show changeset information by line for each file
 
     List changes in files, showing the revision id responsible for
     each line
 
     This command is useful for discovering when a change was made and
     by whom.
 
     Without the -a/--text option, annotate will avoid processing files
     it detects as binary. With -a, annotate will annotate the file
     anyway, although the results will probably be neither useful
     nor desirable.
 
     Returns 0 on success.
     """
     if opts.get('follow'):
         # --follow is deprecated and now just an alias for -f/--file
         # to mimic the behavior of Mercurial before version 1.5
         opts['file'] = 1
 
     datefunc = ui.quiet and util.shortdate or util.datestr
     getdate = util.cachefunc(lambda x: datefunc(x[0].date()))
 
     if not pats:
         raise util.Abort(_('at least one filename or pattern is required'))
 
     opmap = [('user', lambda x: ui.shortuser(x[0].user())),
              ('number', lambda x: str(x[0].rev())),
              ('changeset', lambda x: short(x[0].node())),
              ('date', getdate),
              ('file', lambda x: x[0].path()),
             ]
 
     if (not opts.get('user') and not opts.get('changeset')
         and not opts.get('date') and not opts.get('file')):
         opts['number'] = 1
 
     linenumber = opts.get('line_number') is not None
     if linenumber and (not opts.get('changeset')) and (not opts.get('number')):
         raise util.Abort(_('at least one of -n/-c is required for -l'))
 
     funcmap = [func for op, func in opmap if opts.get(op)]
     if linenumber:
         lastfunc = funcmap[-1]
         funcmap[-1] = lambda x: "%s:%s" % (lastfunc(x), x[1])
 
     ctx = repo[opts.get('rev')]
     m = cmdutil.match(repo, pats, opts)
     follow = not opts.get('no_follow')
     for abs in ctx.walk(m):
         fctx = ctx[abs]
         if not opts.get('text') and util.binary(fctx.data()):
             ui.write(_("%s: binary file\n") % ((pats and m.rel(abs)) or abs))
             continue
 
         lines = fctx.annotate(follow=follow, linenumber=linenumber)
         pieces = []
 
         for f in funcmap:
             l = [f(n) for n, dummy in lines]
             if l:
                 sized = [(x, encoding.colwidth(x)) for x in l]
                 ml = max([w for x, w in sized])
                 pieces.append(["%s%s" % (' ' * (ml - w), x) for x, w in sized])
 
         if pieces:
             for p, l in zip(zip(*pieces), lines):
                 ui.write("%s: %s" % (" ".join(p), l[1]))
 
 def archive(ui, repo, dest, **opts):
     '''create an unversioned archive of a repository revision
 
     By default, the revision used is the parent of the working
     directory; use -r/--rev to specify a different revision.
 
     The archive type is automatically detected based on file
     extension (or override using -t/--type).
 
     Valid types are:
 
     :``files``: a directory full of files (default)
     :``tar``:   tar archive, uncompressed
     :``tbz2``:  tar archive, compressed using bzip2
     :``tgz``:   tar archive, compressed using gzip
     :``uzip``:  zip archive, uncompressed
     :``zip``:   zip archive, compressed using deflate
 
     The exact name of the destination archive or directory is given
     using a format string; see :hg:`help export` for details.
 
     Each member added to an archive file has a directory prefix
     prepended. Use -p/--prefix to specify a format string for the
     prefix. The default is the basename of the archive, with suffixes
     removed.
 
     Returns 0 on success.
     '''
 
     ctx = repo[opts.get('rev')]
     if not ctx:
         raise util.Abort(_('no working directory: please specify a revision'))
     node = ctx.node()
     dest = cmdutil.make_filename(repo, dest, node)
     if os.path.realpath(dest) == repo.root:
         raise util.Abort(_('repository root cannot be destination'))
 
     kind = opts.get('type') or archival.guesskind(dest) or 'files'
     prefix = opts.get('prefix')
 
     if dest == '-':
         if kind == 'files':
             raise util.Abort(_('cannot archive plain files to stdout'))
         dest = sys.stdout
         if not prefix:
             prefix = os.path.basename(repo.root) + '-%h'
 
     prefix = cmdutil.make_filename(repo, prefix, node)
     matchfn = cmdutil.match(repo, [], opts)
     archival.archive(repo, dest, node, kind, not opts.get('no_decode'),
                      matchfn, prefix, subrepos=opts.get('subrepos'))
 
 def backout(ui, repo, node=None, rev=None, **opts):
     '''reverse effect of earlier changeset
 
-    Commit the backed out changes as a new changeset. The new
-    changeset is a child of the backed out changeset.
-
-    If you backout a changeset other than the tip, a new head is
-    created. This head will be the new tip and you should merge this
-    backout changeset with another head.
-
+    The backout command merges the reverse effect of the reverted
+    changeset into the working directory.
+
+    With the --merge option, it first commits the reverted changes
+    as a new changeset. This new changeset is a child of the reverted
+    changeset.
     The --merge option remembers the parent of the working directory
     before starting the backout, then merges the new head with that
-    changeset afterwards. This saves you from doing the merge by hand.
-    The result of this merge is not committed, as with a normal merge.
+    changeset afterwards.
+    This will result in an explicit merge in the history.
+
+    If you backout a changeset other than the original parent of the
+    working directory, the result of this merge is not committed,
+    as with a normal merge. Otherwise, no merge is needed and the
+    commit is automatic.
+
+    Note that the default behavior (without --merge) has changed in
+    version 1.7. To restore the previous default behavior, use
+    :hg:`backout --merge` and then :hg:`update --clean .` to get rid of
+    the ongoing merge.
 
     See :hg:`help dates` for a list of formats valid for -d/--date.
 
     Returns 0 on success.
     '''
     if rev and node:
         raise util.Abort(_("please specify just one revision"))
 
     if not rev:
         rev = node
 
     if not rev:
         raise util.Abort(_("please specify a revision to backout"))
 
     date = opts.get('date')
     if date:
         opts['date'] = util.parsedate(date)
 
     cmdutil.bail_if_changed(repo)
     node = repo.lookup(rev)
 
     op1, op2 = repo.dirstate.parents()
     a = repo.changelog.ancestor(op1, node)
     if a != node:
         raise util.Abort(_('cannot backout change on a different branch'))
 
     p1, p2 = repo.changelog.parents(node)
     if p1 == nullid:
         raise util.Abort(_('cannot backout a change with no parents'))
     if p2 != nullid:
         if not opts.get('parent'):
             raise util.Abort(_('cannot backout a merge changeset without '
                                '--parent'))
         p = repo.lookup(opts['parent'])
         if p not in (p1, p2):
             raise util.Abort(_('%s is not a parent of %s') %
                              (short(p), short(node)))
         parent = p
     else:
         if opts.get('parent'):
             raise util.Abort(_('cannot use --parent on non-merge changeset'))
         parent = p1
 
     # the backout should appear on the same branch
     branch = repo.dirstate.branch()
     hg.clean(repo, node, show_stats=False)
     repo.dirstate.setbranch(branch)
     revert_opts = opts.copy()
     revert_opts['date'] = None
     revert_opts['all'] = True
     revert_opts['rev'] = hex(parent)
     revert_opts['no_backup'] = None
     revert(ui, repo, **revert_opts)
+    if not opts.get('merge') and op1 != node:
+        return hg.update(repo, op1)
+
     commit_opts = opts.copy()
     commit_opts['addremove'] = False
     if not commit_opts['message'] and not commit_opts['logfile']:
         # we don't translate commit messages
         commit_opts['message'] = "Backed out changeset %s" % short(node)
         commit_opts['force_editor'] = True
     commit(ui, repo, **commit_opts)
     def nice(node):
         return '%d:%s' % (repo.changelog.rev(node), short(node))
     ui.status(_('changeset %s backs out changeset %s\n') %
               (nice(repo.changelog.tip()), nice(node)))
-    if op1 != node:
+    if opts.get('merge') and op1 != node:
         hg.clean(repo, op1, show_stats=False)
-        if opts.get('merge'):
             ui.status(_('merging with changeset %s\n')
                       % nice(repo.changelog.tip()))
-            hg.merge(repo, hex(repo.changelog.tip()))
-        else:
-            ui.status(_('the backout changeset is a new head - '
-                        'do not forget to merge\n'))
-            ui.status(_('(use "backout --merge" '
-                        'if you want to auto-merge)\n'))
+        return hg.merge(repo, hex(repo.changelog.tip()))
+    return 0
 
 def bisect(ui, repo, rev=None, extra=None, command=None,
                reset=None, good=None, bad=None, skip=None, noupdate=None):
     """subdivision search of changesets
 
     This command helps to find changesets which introduce problems. To
     use, mark the earliest changeset you know exhibits the problem as
     bad, then mark the latest changeset which is free from the problem
     as good. Bisect will update your working directory to a revision
     for testing (unless the -U/--noupdate option is specified). Once
     you have performed tests, mark the working directory as good or
     bad, and bisect will either update to another candidate changeset
     or announce that it has found the bad revision.
 
     As a shortcut, you can also use the revision argument to mark a
     revision as good or bad without checking it out first.
 
     If you supply a command, it will be used for automatic bisection.
     Its exit status will be used to mark revisions as good or bad:
     status 0 means good, 125 means to skip the revision, 127
     (command not found) will abort the bisection, and any other
     non-zero exit status means the revision is bad.
 
     Returns 0 on success.
     """
     def print_result(nodes, good):
         displayer = cmdutil.show_changeset(ui, repo, {})
         if len(nodes) == 1:
             # narrowed it down to a single revision
             if good:
                 ui.write(_("The first good revision is:\n"))
             else:
                 ui.write(_("The first bad revision is:\n"))
             displayer.show(repo[nodes[0]])
             parents = repo[nodes[0]].parents()
             if len(parents) > 1:
                 side = good and state['bad'] or state['good']
                 num = len(set(i.node() for i in parents) & set(side))
                 if num == 1:
                     common = parents[0].ancestor(parents[1])
                     ui.write(_('Not all ancestors of this changeset have been'
                                ' checked.\nTo check the other ancestors, start'
                                ' from the common ancestor, %s.\n' % common))
         else:
             # multiple possible revisions
             if good:
                 ui.write(_("Due to skipped revisions, the first "
                         "good revision could be any of:\n"))
             else:
                 ui.write(_("Due to skipped revisions, the first "
                         "bad revision could be any of:\n"))
             for n in nodes:
                 displayer.show(repo[n])
         displayer.close()
 
     def check_state(state, interactive=True):
         if not state['good'] or not state['bad']:
             if (good or bad or skip or reset) and interactive:
                 return
             if not state['good']:
                 raise util.Abort(_('cannot bisect (no known good revisions)'))
             else:
                 raise util.Abort(_('cannot bisect (no known bad revisions)'))
         return True
 
     # backward compatibility
     if rev in "good bad reset init".split():
         ui.warn(_("(use of 'hg bisect <cmd>' is deprecated)\n"))
         cmd, rev, extra = rev, extra, None
         if cmd == "good":
             good = True
         elif cmd == "bad":
             bad = True
         else:
             reset = True
     elif extra or good + bad + skip + reset + bool(command) > 1:
         raise util.Abort(_('incompatible arguments'))
 
     if reset:
         p = repo.join("bisect.state")
         if os.path.exists(p):
             os.unlink(p)
         return
 
     state = hbisect.load_state(repo)
 
     if command:
         changesets = 1
         try:
             while changesets:
                 # update state
                 status = util.system(command)
                 if status == 125:
                     transition = "skip"
                 elif status == 0:
                     transition = "good"
                 # status < 0 means process was killed
                 elif status == 127:
                     raise util.Abort(_("failed to execute %s") % command)
                 elif status < 0:
                     raise util.Abort(_("%s killed") % command)
                 else:
                     transition = "bad"
                 ctx = repo[rev or '.']
                 state[transition].append(ctx.node())
                 ui.status(_('Changeset %d:%s: %s\n') % (ctx, ctx, transition))
                 check_state(state, interactive=False)
                 # bisect
                 nodes, changesets, good = hbisect.bisect(repo.changelog, state)
                 # update to next check
                 cmdutil.bail_if_changed(repo)
                 hg.clean(repo, nodes[0], show_stats=False)
         finally:
             hbisect.save_state(repo, state)
         print_result(nodes, good)
         return
 
     # update state
 
     if rev:
         nodes = [repo.lookup(i) for i in cmdutil.revrange(repo, [rev])]
     else:
         nodes = [repo.lookup('.')]
 
     if good or bad or skip:
         if good:
             state['good'] += nodes
         elif bad:
             state['bad'] += nodes
         elif skip:
             state['skip'] += nodes
         hbisect.save_state(repo, state)
 
     if not check_state(state):
         return
 
     # actually bisect
     nodes, changesets, good = hbisect.bisect(repo.changelog, state)
     if changesets == 0:
         print_result(nodes, good)
     else:
         assert len(nodes) == 1 # only a single node can be tested next
         node = nodes[0]
         # compute the approximate number of remaining tests
         tests, size = 0, 2
         while size <= changesets:
             tests, size = tests + 1, size * 2
         rev = repo.changelog.rev(node)
         ui.write(_("Testing changeset %d:%s "
                    "(%d changesets remaining, ~%d tests)\n")
                  % (rev, short(node), changesets, tests))
         if not noupdate:
             cmdutil.bail_if_changed(repo)
             return hg.clean(repo, node)
 
 def branch(ui, repo, label=None, **opts):
     """set or show the current branch name
 
     With no argument, show the current branch name. With one argument,
     set the working directory branch name (the branch will not exist
     in the repository until the next commit). Standard practice
     recommends that primary development take place on the 'default'
     branch.
 
     Unless -f/--force is specified, branch will not let you set a
     branch name that already exists, even if it's inactive.
 
     Use -C/--clean to reset the working directory branch to that of
     the parent of the working directory, negating a previous branch
     change.
 
     Use the command :hg:`update` to switch to an existing branch. Use
     :hg:`commit --close-branch` to mark this branch as closed.
 
     Returns 0 on success.
     """
 
     if opts.get('clean'):
         label = repo[None].parents()[0].branch()
         repo.dirstate.setbranch(label)
         ui.status(_('reset working directory to branch %s\n') % label)
     elif label:
         utflabel = encoding.fromlocal(label)
         if not opts.get('force') and utflabel in repo.branchtags():
             if label not in [p.branch() for p in repo.parents()]:
                 raise util.Abort(_('a branch of the same name already exists'
                                    " (use 'hg update' to switch to it)"))
         repo.dirstate.setbranch(utflabel)
         ui.status(_('marked working directory as branch %s\n') % label)
     else:
         ui.write("%s\n" % encoding.tolocal(repo.dirstate.branch()))
 
 def branches(ui, repo, active=False, closed=False):
     """list repository named branches
 
     List the repository's named branches, indicating which ones are
     inactive. If -c/--closed is specified, also list branches which have
     been marked closed (see :hg:`commit --close-branch`).
 
     If -a/--active is specified, only show active branches. A branch
     is considered active if it contains repository heads.
 
     Use the command :hg:`update` to switch to an existing branch.
 
     Returns 0.
     """
 
     hexfunc = ui.debugflag and hex or short
     activebranches = [repo[n].branch() for n in repo.heads()]
     def testactive(tag, node):
         realhead = tag in activebranches
         open = node in repo.branchheads(tag, closed=False)
         return realhead and open
     branches = sorted([(testactive(tag, node), repo.changelog.rev(node), tag)
                           for tag, node in repo.branchtags().items()],
                       reverse=True)
 
     for isactive, node, tag in branches:
         if (not active) or isactive:
             encodedtag = encoding.tolocal(tag)
             if ui.quiet:
                 ui.write("%s\n" % encodedtag)
             else:
                 hn = repo.lookup(node)
                 if isactive:
                     label = 'branches.active'
                     notice = ''
                 elif hn not in repo.branchheads(tag, closed=False):
                     if not closed:
                         continue
                     label = 'branches.closed'
                     notice = _(' (closed)')
                 else:
                     label = 'branches.inactive'
                     notice = _(' (inactive)')
                 if tag == repo.dirstate.branch():
                     label = 'branches.current'
                 rev = str(node).rjust(31 - encoding.colwidth(encodedtag))
                 rev = ui.label('%s:%s' % (rev, hexfunc(hn)), 'log.changeset')
                 encodedtag = ui.label(encodedtag, label)
                 ui.write("%s %s%s\n" % (encodedtag, rev, notice))
 
 def bundle(ui, repo, fname, dest=None, **opts):
     """create a changegroup file
 
     Generate a compressed changegroup file collecting changesets not
     known to be in another repository.
 
     If you omit the destination repository, then hg assumes the
     destination will have all the nodes you specify with --base
     parameters. To create a bundle containing all changesets, use
     -a/--all (or --base null).
 
     You can change compression method with the -t/--type option.
     The available compression methods are: none, bzip2, and
     gzip (by default, bundles are compressed using bzip2).
 
     The bundle file can then be transferred using conventional means
     and applied to another repository with the unbundle or pull
     command. This is useful when direct push and pull are not
     available or when exporting an entire repository is undesirable.
 
     Applying bundles preserves all changeset contents including
     permissions, copy/rename information, and revision history.
 
     Returns 0 on success, 1 if no changes found.
     """
     revs = opts.get('rev') or None
     if opts.get('all'):
         base = ['null']
     else:
         base = opts.get('base')
     if base:
         if dest:
             raise util.Abort(_("--base is incompatible with specifying "
                                "a destination"))
         base = [repo.lookup(rev) for rev in base]
         # create the right base
         # XXX: nodesbetween / changegroup* should be "fixed" instead
         o = []
         has = set((nullid,))
         for n in base:
             has.update(repo.changelog.reachable(n))
         if revs:
             revs = [repo.lookup(rev) for rev in revs]
             visit = revs[:]
             has.difference_update(visit)
         else:
             visit = repo.changelog.heads()
         seen = {}
         while visit:
             n = visit.pop(0)
             parents = [p for p in repo.changelog.parents(n) if p not in has]
             if len(parents) == 0:
                 if n not in has:
                     o.append(n)
             else:
                 for p in parents:
                     if p not in seen:
                         seen[p] = 1
                         visit.append(p)
     else:
         dest = ui.expandpath(dest or 'default-push', dest or 'default')
         dest, branches = hg.parseurl(dest, opts.get('branch'))
         other = hg.repository(hg.remoteui(repo, opts), dest)
         revs, checkout = hg.addbranchrevs(repo, other, branches, revs)
         if revs:
             revs = [repo.lookup(rev) for rev in revs]
         o = discovery.findoutgoing(repo, other, force=opts.get('force'))
 
     if not o:
         ui.status(_("no changes found\n"))
         return 1
 
     if revs:
         cg = repo.changegroupsubset(o, revs, 'bundle')
     else:
         cg = repo.changegroup(o, 'bundle')
 
     bundletype = opts.get('type', 'bzip2').lower()
     btypes = {'none': 'HG10UN', 'bzip2': 'HG10BZ', 'gzip': 'HG10GZ'}
     bundletype = btypes.get(bundletype)
     if bundletype not in changegroup.bundletypes:
         raise util.Abort(_('unknown bundle type specified with --type'))
 
     changegroup.writebundle(cg, fname, bundletype)
 
 def cat(ui, repo, file1, *pats, **opts):
     """output the current or given revision of files
 
     Print the specified files as they were at the given revision. If
     no revision is given, the parent of the working directory is used,
     or tip if no revision is checked out.
 
     Output may be to a file, in which case the name of the file is
     given using a format string. The formatting rules are the same as
     for the export command, with the following additions:
 
     :``%s``: basename of file being printed
     :``%d``: dirname of file being printed, or '.' if in repository root
     :``%p``: root-relative path name of file being printed
 
     Returns 0 on success.
     """
     ctx = cmdutil.revsingle(repo, opts.get('rev'))
     err = 1
     m = cmdutil.match(repo, (file1,) + pats, opts)
     for abs in ctx.walk(m):
         fp = cmdutil.make_file(repo, opts.get('output'), ctx.node(), pathname=abs)
         data = ctx[abs].data()
         if opts.get('decode'):
             data = repo.wwritedata(abs, data)
         fp.write(data)
         err = 0
     return err
 
 def clone(ui, source, dest=None, **opts):
     """make a copy of an existing repository
 
     Create a copy of an existing repository in a new directory.
 
     If no destination directory name is specified, it defaults to the
     basename of the source.
 
     The location of the source is added to the new repository's
     .hg/hgrc file, as the default to be used for future pulls.
 
     See :hg:`help urls` for valid source format details.
 
     It is possible to specify an ``ssh://`` URL as the destination, but no
     .hg/hgrc and working directory will be created on the remote side.
     Please see :hg:`help urls` for important details about ``ssh://`` URLs.
 
     A set of changesets (tags, or branch names) to pull may be specified
     by listing each changeset (tag, or branch name) with -r/--rev.
     If -r/--rev is used, the cloned repository will contain only a subset
     of the changesets of the source repository. Only the set of changesets
     defined by all -r/--rev options (including all their ancestors)
     will be pulled into the destination repository.
     No subsequent changesets (including subsequent tags) will be present
     in the destination.
 
     Using -r/--rev (or 'clone src#rev dest') implies --pull, even for
     local source repositories.
 
     For efficiency, hardlinks are used for cloning whenever the source
     and destination are on the same filesystem (note this applies only
     to the repository data, not to the working directory). Some
     filesystems, such as AFS, implement hardlinking incorrectly, but
     do not report errors. In these cases, use the --pull option to
     avoid hardlinking.
 
     In some cases, you can clone repositories and the working directory
     using full hardlinks with ::
 
       $ cp -al REPO REPOCLONE
 
     This is the fastest way to clone, but it is not always safe. The
     operation is not atomic (making sure REPO is not modified during
     the operation is up to you) and you have to make sure your editor
     breaks hardlinks (Emacs and most Linux Kernel tools do so). Also,
     this is not compatible with certain extensions that place their
     metadata under the .hg directory, such as mq.
 
     Mercurial will update the working directory to the first applicable
     revision from this list:
 
     a) null if -U or the source repository has no changesets
     b) if -u . and the source repository is local, the first parent of
        the source repository's working directory
     c) the changeset specified with -u (if a branch name, this means the
        latest head of that branch)
     d) the changeset specified with -r
     e) the tipmost head specified with -b
     f) the tipmost head specified with the url#branch source syntax
     g) the tipmost head of the default branch
     h) tip
 
     Returns 0 on success.
     """
     if opts.get('noupdate') and opts.get('updaterev'):
         raise util.Abort(_("cannot specify both --noupdate and --updaterev"))
 
     r = hg.clone(hg.remoteui(ui, opts), source, dest,
                  pull=opts.get('pull'),
                  stream=opts.get('uncompressed'),
                  rev=opts.get('rev'),
                  update=opts.get('updaterev') or not opts.get('noupdate'),
                  branch=opts.get('branch'))
 
     return r is None
 
 def commit(ui, repo, *pats, **opts):
     """commit the specified files or all outstanding changes
 
     Commit changes to the given files into the repository. Unlike a
     centralized RCS, this operation is a local operation. See
     :hg:`push` for a way to actively distribute your changes.
 
     If a list of files is omitted, all changes reported by :hg:`status`
     will be committed.
 
     If you are committing the result of a merge, do not provide any
     filenames or -I/-X filters.
 
     If no commit message is specified, Mercurial starts your
     configured editor where you can enter a message. In case your
     commit fails, you will find a backup of your message in
     ``.hg/last-message.txt``.
 
     See :hg:`help dates` for a list of formats valid for -d/--date.
 
     Returns 0 on success, 1 if nothing changed.
     """
     extra = {}
     if opts.get('close_branch'):
         if repo['.'].node() not in repo.branchheads():
             # The topo heads set is included in the branch heads set of the
             # current branch, so it's sufficient to test branchheads
             raise util.Abort(_('can only close branch heads'))
         extra['close'] = 1
     e = cmdutil.commiteditor
     if opts.get('force_editor'):
         e = cmdutil.commitforceeditor
 
     def commitfunc(ui, repo, message, match, opts):
         return repo.commit(message, opts.get('user'), opts.get('date'), match,
                            editor=e, extra=extra)
 
     branch = repo[None].branch()
     bheads = repo.branchheads(branch)
 
     node = cmdutil.commit(ui, repo, commitfunc, pats, opts)
     if not node:
         ui.status(_("nothing changed\n"))
         return 1
 
     ctx = repo[node]
     parents = ctx.parents()
 
     if bheads and not [x for x in parents
                        if x.node() in bheads and x.branch() == branch]:
         ui.status(_('created new head\n'))
         # The message is not printed for initial roots. For the other
         # changesets, it is printed in the following situations:
         #
         # Par column: for the 2 parents with ...
         #   N: null or no parent
         #   B: parent is on another named branch
         #   C: parent is a regular non head changeset
         #   H: parent was a branch head of the current branch
         # Msg column: whether we print "created new head" message
         # In the following, it is assumed that there already exists some
         # initial branch heads of the current branch, otherwise nothing is
         # printed anyway.
         #
         # Par Msg Comment
         # NN   y  additional topo root
         #
         # BN   y  additional branch root
         # CN   y  additional topo head
         # HN   n  usual case
         #
         # BB   y  weird additional branch root
         # CB   y  branch merge
         # HB   n  merge with named branch
         #
         # CC   y  additional head from merge
         # CH   n  merge with a head
         #
         # HH   n  head merge: head count decreases
 
     if not opts.get('close_branch'):
         for r in parents:
             if r.extra().get('close') and r.branch() == branch:
                 ui.status(_('reopening closed branch head %d\n') % r)
 
     if ui.debugflag:
         ui.write(_('committed changeset %d:%s\n') % (int(ctx), ctx.hex()))
     elif ui.verbose:
         ui.write(_('committed changeset %d:%s\n') % (int(ctx), ctx))
 
 def copy(ui, repo, *pats, **opts):
     """mark files as copied for the next commit
 
     Mark dest as having copies of source files. If dest is a
     directory, copies are put in that directory. If dest is a file,
     the source must be a single file.
 
     By default, this command copies the contents of files as they
     exist in the working directory. If invoked with -A/--after, the
     operation is recorded, but no copying is performed.
 
     This command takes effect with the next commit. To undo a copy
     before that, see :hg:`revert`.
 
     Returns 0 on success, 1 if errors are encountered.
     """
     wlock = repo.wlock(False)
     try:
         return cmdutil.copy(ui, repo, pats, opts)
     finally:
         wlock.release()
 
 def debugancestor(ui, repo, *args):
     """find the ancestor revision of two revisions in a given index"""
     if len(args) == 3:
         index, rev1, rev2 = args
         r = revlog.revlog(util.opener(os.getcwd(), audit=False), index)
         lookup = r.lookup
     elif len(args) == 2:
         if not repo:
             raise util.Abort(_("there is no Mercurial repository here "
                                "(.hg not found)"))
         rev1, rev2 = args
         r = repo.changelog
         lookup = repo.lookup
     else:
         raise util.Abort(_('either two or three arguments required'))
     a = r.ancestor(lookup(rev1), lookup(rev2))
     ui.write("%d:%s\n" % (r.rev(a), hex(a)))
 
 def debugbuilddag(ui, repo, text,
                   mergeable_file=False,
                   appended_file=False,
                   overwritten_file=False,
                   new_file=False):
     """builds a repo with a given dag from scratch in the current empty repo
 
     Elements:
 
      - "+n" is a linear run of n nodes based on the current default parent
      - "." is a single node based on the current default parent
      - "$" resets the default parent to null (implied at the start);
            otherwise the default parent is always the last node created
      - "<p" sets the default parent to the backref p
      - "*p" is a fork at parent p, which is a backref
      - "*p1/p2" is a merge of parents p1 and p2, which are backrefs
      - "/p2" is a merge of the preceding node and p2
      - ":tag" defines a local tag for the preceding node
      - "@branch" sets the named branch for subsequent nodes
      - "!command" runs the command using your shell
      - "!!my command\\n" is like "!", but to the end of the line
      - "#...\\n" is a comment up to the end of the line
 
     Whitespace between the above elements is ignored.
 
     A backref is either
 
      - a number n, which references the node curr-n, where curr is the current
        node, or
      - the name of a local tag you placed earlier using ":tag", or
      - empty to denote the default parent.
 
     All string valued-elements are either strictly alphanumeric, or must
     be enclosed in double quotes ("..."), with "\\" as escape character.
 
     Note that the --overwritten-file and --appended-file options imply the
     use of "HGMERGE=internal:local" during DAG buildup.
     """
 
     if not (mergeable_file or appended_file or overwritten_file or new_file):
         raise util.Abort(_('need at least one of -m, -a, -o, -n'))
 
     if len(repo.changelog) > 0:
         raise util.Abort(_('repository is not empty'))
 
     if overwritten_file or appended_file:
         # we don't want to fail in merges during buildup
         os.environ['HGMERGE'] = 'internal:local'
 
     def writefile(fname, text, fmode="wb"):
         f = open(fname, fmode)
         try:
             f.write(text)
         finally:
             f.close()
 
     if mergeable_file:
         linesperrev = 2
         # determine number of revs in DAG
         n = 0
         for type, data in dagparser.parsedag(text):
             if type == 'n':
                 n += 1
         # make a file with k lines per rev
         writefile("mf", "\n".join(str(i) for i in xrange(0, n * linesperrev))
                   + "\n")
 
     at = -1
     atbranch = 'default'
     for type, data in dagparser.parsedag(text):
         if type == 'n':
             ui.status('node %s\n' % str(data))
             id, ps = data
             p1 = ps[0]
             if p1 != at:
                 update(ui, repo, node=str(p1), clean=True)
                 at = p1
             if repo.dirstate.branch() != atbranch:
                 branch(ui, repo, atbranch, force=True)
             if len(ps) > 1:
                 p2 = ps[1]
                 merge(ui, repo, node=p2)
 
             if mergeable_file:
                 f = open("mf", "rb+")
                 try:
                     lines = f.read().split("\n")
                     lines[id * linesperrev] += " r%i" % id
                     f.seek(0)
                     f.write("\n".join(lines))
                 finally:
                     f.close()
 
             if appended_file:
                 writefile("af", "r%i\n" % id, "ab")
 
             if overwritten_file:
                 writefile("of", "r%i\n" % id)
 
             if new_file:
                 writefile("nf%i" % id, "r%i\n" % id)
 
             commit(ui, repo, addremove=True, message="r%i" % id, date=(id, 0))
             at = id
         elif type == 'l':
             id, name = data
             ui.status('tag %s\n' % name)
             tag(ui, repo, name, local=True)
         elif type == 'a':
             ui.status('branch %s\n' % data)
             atbranch = data
         elif type in 'cC':
             r = util.system(data, cwd=repo.root)
             if r:
                 desc, r = util.explain_exit(r)
                 raise util.Abort(_('%s command %s') % (data, desc))
 
 def debugcommands(ui, cmd='', *args):
     """list all available commands and options"""
     for cmd, vals in sorted(table.iteritems()):
         cmd = cmd.split('|')[0].strip('^')
         opts = ', '.join([i[1] for i in vals[1]])
         ui.write('%s: %s\n' % (cmd, opts))
 
 def debugcomplete(ui, cmd='', **opts):
     """returns the completion list associated with the given command"""
 
     if opts.get('options'):
         options = []
         otables = [globalopts]
         if cmd:
             aliases, entry = cmdutil.findcmd(cmd, table, False)
             otables.append(entry[1])
         for t in otables:
             for o in t:
                 if "(DEPRECATED)" in o[3]:
                     continue
                 if o[0]:
                     options.append('-%s' % o[0])
                 options.append('--%s' % o[1])
         ui.write("%s\n" % "\n".join(options))
         return
 
     cmdlist = cmdutil.findpossible(cmd, table)
     if ui.verbose:
         cmdlist = [' '.join(c[0]) for c in cmdlist.values()]
     ui.write("%s\n" % "\n".join(sorted(cmdlist)))
 
 def debugfsinfo(ui, path = "."):
     """show information detected about current filesystem"""
     open('.debugfsinfo', 'w').write('')
     ui.write('exec: %s\n' % (util.checkexec(path) and 'yes' or 'no'))
     ui.write('symlink: %s\n' % (util.checklink(path) and 'yes' or 'no'))
     ui.write('case-sensitive: %s\n' % (util.checkcase('.debugfsinfo')
                                 and 'yes' or 'no'))
     os.unlink('.debugfsinfo')
 
 def debugrebuildstate(ui, repo, rev="tip"):
     """rebuild the dirstate as it would look like for the given revision"""
     ctx = repo[rev]
     wlock = repo.wlock()
     try:
         repo.dirstate.rebuild(ctx.node(), ctx.manifest())
     finally:
         wlock.release()
 
 def debugcheckstate(ui, repo):
     """validate the correctness of the current dirstate"""
     parent1, parent2 = repo.dirstate.parents()
     m1 = repo[parent1].manifest()
     m2 = repo[parent2].manifest()
     errors = 0
     for f in repo.dirstate:
         state = repo.dirstate[f]
         if state in "nr" and f not in m1:
             ui.warn(_("%s in state %s, but not in manifest1\n") % (f, state))
             errors += 1
         if state in "a" and f in m1:
             ui.warn(_("%s in state %s, but also in manifest1\n") % (f, state))
             errors += 1
         if state in "m" and f not in m1 and f not in m2:
             ui.warn(_("%s in state %s, but not in either manifest\n") %
                     (f, state))
             errors += 1
     for f in m1:
         state = repo.dirstate[f]
         if state not in "nrm":
             ui.warn(_("%s in manifest1, but listed as state %s") % (f, state))
             errors += 1
     if errors:
         error = _(".hg/dirstate inconsistent with current parent's manifest")
         raise util.Abort(error)
 
 def showconfig(ui, repo, *values, **opts):
     """show combined config settings from all hgrc files
 
     With no arguments, print names and values of all config items.
 
     With one argument of the form section.name, print just the value
     of that config item.
 
     With multiple arguments, print names and values of all config
     items with matching section names.
 
     With --debug, the source (filename and line number) is printed
     for each config item.
 
     Returns 0 on success.
     """
 
     for f in util.rcpath():
         ui.debug(_('read config from: %s\n') % f)
     untrusted = bool(opts.get('untrusted'))
     if values:
         sections = [v for v in values if '.' not in v]
         items = [v for v in values if '.' in v]
         if len(items) > 1 or items and sections:
             raise util.Abort(_('only one config item permitted'))
     for section, name, value in ui.walkconfig(untrusted=untrusted):
         sectname = section + '.' + name
         if values:
             for v in values:
                 if v == section:
                     ui.debug('%s: ' %
                              ui.configsource(section, name, untrusted))
                     ui.write('%s=%s\n' % (sectname, value))
                 elif v == sectname:
                     ui.debug('%s: ' %
                              ui.configsource(section, name, untrusted))
                     ui.write(value, '\n')
         else:
             ui.debug('%s: ' %
                      ui.configsource(section, name, untrusted))
             ui.write('%s=%s\n' % (sectname, value))
 
 def debugpushkey(ui, repopath, namespace, *keyinfo):
     '''access the pushkey key/value protocol
 
     With two args, list the keys in the given namespace.
 
     With five args, set a key to new if it currently is set to old.
     Reports success or failure.
     '''
 
     target = hg.repository(ui, repopath)
     if keyinfo:
         key, old, new = keyinfo
         r = target.pushkey(namespace, key, old, new)
         ui.status(str(r) + '\n')
         return not(r)
     else:
         for k, v in target.listkeys(namespace).iteritems():
             ui.write("%s\t%s\n" % (k.encode('string-escape'),
                                    v.encode('string-escape')))
 
 def debugrevspec(ui, repo, expr):
     '''parse and apply a revision specification'''
     if ui.verbose:
         tree = revset.parse(expr)
         ui.note(tree, "\n")
     func = revset.match(expr)
     for c in func(repo, range(len(repo))):
         ui.write("%s\n" % c)
 
 def debugsetparents(ui, repo, rev1, rev2=None):
     """manually set the parents of the current working directory
 
     This is useful for writing repository conversion tools, but should
     be used with care.
 
     Returns 0 on success.
     """
 
     if not rev2:
         rev2 = hex(nullid)
 
     wlock = repo.wlock()
     try:
         repo.dirstate.setparents(repo.lookup(rev1), repo.lookup(rev2))
     finally:
         wlock.release()
 
 def debugstate(ui, repo, nodates=None):
     """show the contents of the current dirstate"""
     timestr = ""
     showdate = not nodates
     for file_, ent in sorted(repo.dirstate._map.iteritems()):
         if showdate:
             if ent[3] == -1:
                 # Pad or slice to locale representation
                 locale_len = len(time.strftime("%Y-%m-%d %H:%M:%S ",
                                                time.localtime(0)))
                 timestr = 'unset'
                 timestr = (timestr[:locale_len] +
                            ' ' * (locale_len - len(timestr)))
             else:
                 timestr = time.strftime("%Y-%m-%d %H:%M:%S ",
                                         time.localtime(ent[3]))
         if ent[1] & 020000:
             mode = 'lnk'
         else:
             mode = '%3o' % (ent[1] & 0777)
         ui.write("%c %s %10d %s%s\n" % (ent[0], mode, ent[2], timestr, file_))
     for f in repo.dirstate.copies():
         ui.write(_("copy: %s -> %s\n") % (repo.dirstate.copied(f), f))
 
 def debugsub(ui, repo, rev=None):
     if rev == '':
         rev = None
     for k, v in sorted(repo[rev].substate.items()):
         ui.write('path %s\n' % k)
         ui.write(' source   %s\n' % v[0])
         ui.write(' revision %s\n' % v[1])
 
 def debugdag(ui, repo, file_=None, *revs, **opts):
     """format the changelog or an index DAG as a concise textual description
 
     If you pass a revlog index, the revlog's DAG is emitted. If you list
     revision numbers, they get labelled in the output as rN.
 
     Otherwise, the changelog DAG of the current repo is emitted.
     """
     spaces = opts.get('spaces')
     dots = opts.get('dots')
     if file_:
         rlog = revlog.revlog(util.opener(os.getcwd(), audit=False), file_)
         revs = set((int(r) for r in revs))
         def events():
             for r in rlog:
                 yield 'n', (r, list(set(p for p in rlog.parentrevs(r) if p != -1)))
                 if r in revs:
                     yield 'l', (r, "r%i" % r)
     elif repo:
         cl = repo.changelog
         tags = opts.get('tags')
         branches = opts.get('branches')
         if tags:
             labels = {}
             for l, n in repo.tags().items():
                 labels.setdefault(cl.rev(n), []).append(l)
         def events():
             b = "default"
             for r in cl:
                 if branches:
                     newb = cl.read(cl.node(r))[5]['branch']
                     if newb != b:
                         yield 'a', newb
                         b = newb
                 yield 'n', (r, list(set(p for p in cl.parentrevs(r) if p != -1)))
                 if tags:
                     ls = labels.get(r)
                     if ls:
                         for l in ls:
                             yield 'l', (r, l)
     else:
         raise util.Abort(_('need repo for changelog dag'))
 
     for line in dagparser.dagtextlines(events(),
                                        addspaces=spaces,
                                        wraplabels=True,
                                        wrapannotations=True,
                                        wrapnonlinear=dots,
                                        usedots=dots,
                                        maxlinewidth=70):
         ui.write(line)
         ui.write("\n")
 
 def debugdata(ui, repo, file_, rev):
     """dump the contents of a data file revision"""
     r = None
     if repo:
         filelog = repo.file(file_)
         if len(filelog):
             r = filelog
     if not r:
         r = revlog.revlog(util.opener(os.getcwd(), audit=False), file_[:-2] + ".i")
     try:
         ui.write(r.revision(r.lookup(rev)))
     except KeyError:
         raise util.Abort(_('invalid revision identifier %s') % rev)
 
 def debugdate(ui, date, range=None, **opts):
     """parse and display a date"""
     if opts["extended"]:
         d = util.parsedate(date, util.extendeddateformats)
     else:
         d = util.parsedate(date)
     ui.write("internal: %s %s\n" % d)
     ui.write("standard: %s\n" % util.datestr(d))
     if range:
         m = util.matchdate(range)
         ui.write("match: %s\n" % m(d[0]))
 
 def debugindex(ui, repo, file_):
     """dump the contents of an index file"""
     r = None
     if repo:
         filelog = repo.file(file_)
         if len(filelog):
             r = filelog
     if not r:
         r = revlog.revlog(util.opener(os.getcwd(), audit=False), file_)
     ui.write("   rev    offset  length   base linkrev"
              " nodeid       p1           p2\n")
     for i in r:
         node = r.node(i)
         try:
             pp = r.parents(node)
         except:
             pp = [nullid, nullid]
         ui.write("% 6d % 9d % 7d % 6d % 7d %s %s %s\n" % (
                 i, r.start(i), r.length(i), r.base(i), r.linkrev(i),
             short(node), short(pp[0]), short(pp[1])))
 
 def debugindexdot(ui, repo, file_):
     """dump an index DAG as a graphviz dot file"""
     r = None
     if repo:
         filelog = repo.file(file_)
         if len(filelog):
             r = filelog
     if not r:
         r = revlog.revlog(util.opener(os.getcwd(), audit=False), file_)
     ui.write("digraph G {\n")
     for i in r:
         node = r.node(i)
         pp = r.parents(node)
         ui.write("\t%d -> %d\n" % (r.rev(pp[0]), i))
         if pp[1] != nullid:
             ui.write("\t%d -> %d\n" % (r.rev(pp[1]), i))
     ui.write("}\n")
 
 def debuginstall(ui):
     '''test Mercurial installation
 
     Returns 0 on success.
     '''
 
     def writetemp(contents):
         (fd, name) = tempfile.mkstemp(prefix="hg-debuginstall-")
         f = os.fdopen(fd, "wb")
         f.write(contents)
         f.close()
         return name
 
     problems = 0
 
     # encoding
     ui.status(_("Checking encoding (%s)...\n") % encoding.encoding)
     try:
         encoding.fromlocal("test")
     except util.Abort, inst:
         ui.write(" %s\n" % inst)
         ui.write(_(" (check that your locale is properly set)\n"))
         problems += 1
 
     # compiled modules
     ui.status(_("Checking installed modules (%s)...\n")
               % os.path.dirname(__file__))
     try:
         import bdiff, mpatch, base85, osutil
     except Exception, inst:
         ui.write(" %s\n" % inst)
         ui.write(_(" One or more extensions could not be found"))
         ui.write(_(" (check that you compiled the extensions)\n"))
         problems += 1
 
     # templates
     ui.status(_("Checking templates...\n"))
     try:
         import templater
         templater.templater(templater.templatepath("map-cmdline.default"))
     except Exception, inst:
         ui.write(" %s\n" % inst)
         ui.write(_(" (templates seem to have been installed incorrectly)\n"))
         problems += 1
 
     # patch
     ui.status(_("Checking patch...\n"))
     patchproblems = 0
     a = "1\n2\n3\n4\n"
     b = "1\n2\n3\ninsert\n4\n"
     fa = writetemp(a)
     d = mdiff.unidiff(a, None, b, None, os.path.basename(fa),
         os.path.basename(fa))
     fd = writetemp(d)
 
     files = {}
     try:
         patch.patch(fd, ui, cwd=os.path.dirname(fa), files=files)
     except util.Abort, e:
         ui.write(_(" patch call failed:\n"))
         ui.write(" " + str(e) + "\n")
         patchproblems += 1
     else:
         if list(files) != [os.path.basename(fa)]:
             ui.write(_(" unexpected patch output!\n"))
             patchproblems += 1
         a = open(fa).read()
         if a != b:
             ui.write(_(" patch test failed!\n"))
             patchproblems += 1
 
     if patchproblems:
         if ui.config('ui', 'patch'):
             ui.write(_(" (Current patch tool may be incompatible with patch,"
                        " or misconfigured. Please check your configuration"
                        " file)\n"))
         else:
             ui.write(_(" Internal patcher failure, please report this error"
                        " to http://mercurial.selenic.com/bts/\n"))
     problems += patchproblems
 
     os.unlink(fa)
     os.unlink(fd)
 
     # editor
     ui.status(_("Checking commit editor...\n"))
     editor = ui.geteditor()
     cmdpath = util.find_exe(editor) or util.find_exe(editor.split()[0])
     if not cmdpath:
         if editor == 'vi':
             ui.write(_(" No commit editor set and can't find vi in PATH\n"))
             ui.write(_(" (specify a commit editor in your configuration"
                        " file)\n"))
         else:
             ui.write(_(" Can't find editor '%s' in PATH\n") % editor)
             ui.write(_(" (specify a commit editor in your configuration"
                        " file)\n"))
             problems += 1
 
     # check username
     ui.status(_("Checking username...\n"))
     try:
         ui.username()
     except util.Abort, e:
         ui.write(" %s\n" % e)
         ui.write(_(" (specify a username in your configuration file)\n"))
         problems += 1
 
     if not problems:
         ui.status(_("No problems detected\n"))
     else:
         ui.write(_("%s problems detected,"
                    " please check your install!\n") % problems)
 
     return problems
 
 def debugrename(ui, repo, file1, *pats, **opts):
     """dump rename information"""
 
     ctx = repo[opts.get('rev')]
     m = cmdutil.match(repo, (file1,) + pats, opts)
     for abs in ctx.walk(m):
         fctx = ctx[abs]
         o = fctx.filelog().renamed(fctx.filenode())
         rel = m.rel(abs)
         if o:
             ui.write(_("%s renamed from %s:%s\n") % (rel, o[0], hex(o[1])))
         else:
             ui.write(_("%s not renamed\n") % rel)
 
 def debugwalk(ui, repo, *pats, **opts):
     """show how files match on given patterns"""
     m = cmdutil.match(repo, pats, opts)
     items = list(repo.walk(m))
     if not items:
         return
     fmt = 'f  %%-%ds  %%-%ds  %%s' % (
         max([len(abs) for abs in items]),
         max([len(m.rel(abs)) for abs in items]))
     for abs in items:
         line = fmt % (abs, m.rel(abs), m.exact(abs) and 'exact' or '')
         ui.write("%s\n" % line.rstrip())
 
 def diff(ui, repo, *pats, **opts):
     """diff repository (or selected files)
 
     Show differences between revisions for the specified files.
 
     Differences between files are shown using the unified diff format.
 
     .. note::
        diff may generate unexpected results for merges, as it will
        default to comparing against the working directory's first
        parent changeset if no revisions are specified.
 
     When two revision arguments are given, then changes are shown
     between those revisions. If only one revision is specified then
     that revision is compared to the working directory, and, when no
     revisions are specified, the working directory files are compared
     to its parent.
 
     Alternatively you can specify -c/--change with a revision to see
     the changes in that changeset relative to its first parent.
 
     Without the -a/--text option, diff will avoid generating diffs of
     files it detects as binary. With -a, diff will generate a diff
     anyway, probably with undesirable results.
 
     Use the -g/--git option to generate diffs in the git extended diff
     format. For more information, read :hg:`help diffs`.
 
     Returns 0 on success.
     """
 
     revs = opts.get('rev')
     change = opts.get('change')
     stat = opts.get('stat')
     reverse = opts.get('reverse')
 
     if revs and change:
         msg = _('cannot specify --rev and --change at the same time')
         raise util.Abort(msg)
     elif change:
         node2 = repo.lookup(change)
         node1 = repo[node2].parents()[0].node()
     else:
         node1, node2 = cmdutil.revpair(repo, revs)
 
     if reverse:
         node1, node2 = node2, node1
 
     diffopts = patch.diffopts(ui, opts)
     m = cmdutil.match(repo, pats, opts)
     cmdutil.diffordiffstat(ui, repo, diffopts, node1, node2, m, stat=stat,
                            listsubrepos=opts.get('subrepos'))
 
 def export(ui, repo, *changesets, **opts):
     """dump the header and diffs for one or more changesets
 
     Print the changeset header and diffs for one or more revisions.
 
     The information shown in the changeset header is: author, date,
     branch name (if non-default), changeset hash, parent(s) and commit
     comment.
 
     .. note::
        export may generate unexpected diff output for merge
        changesets, as it will compare the merge changeset against its
        first parent only.
 
     Output may be to a file, in which case the name of the file is
     given using a format string. The formatting rules are as follows:
 
     :``%%``: literal "%" character
     :``%H``: changeset hash (40 hexadecimal digits)
     :``%N``: number of patches being generated
     :``%R``: changeset revision number
     :``%b``: basename of the exporting repository
     :``%h``: short-form changeset hash (12 hexadecimal digits)
     :``%n``: zero-padded sequence number, starting at 1
     :``%r``: zero-padded changeset revision number
 
     Without the -a/--text option, export will avoid generating diffs
     of files it detects as binary. With -a, export will generate a
     diff anyway, probably with undesirable results.
 
     Use the -g/--git option to generate diffs in the git extended diff
     format. See :hg:`help diffs` for more information.
 
     With the --switch-parent option, the diff will be against the
     second parent. It can be useful to review a merge.
 
     Returns 0 on success.
     """
     changesets += tuple(opts.get('rev', []))
     if not changesets:
         raise util.Abort(_("export requires at least one changeset"))
     revs = cmdutil.revrange(repo, changesets)
     if len(revs) > 1:
         ui.note(_('exporting patches:\n'))
     else:
         ui.note(_('exporting patch:\n'))
     cmdutil.export(repo, revs, template=opts.get('output'),
                  switch_parent=opts.get('switch_parent'),
                  opts=patch.diffopts(ui, opts))
 
 def forget(ui, repo, *pats, **opts):
     """forget the specified files on the next commit
 
     Mark the specified files so they will no longer be tracked
     after the next commit.
 
     This only removes files from the current branch, not from the
     entire project history, and it does not delete them from the
     working directory.
 
     To undo a forget before the next commit, see :hg:`add`.
 
     Returns 0 on success.
     """
 
     if not pats:
         raise util.Abort(_('no files specified'))
 
     m = cmdutil.match(repo, pats, opts)
     s = repo.status(match=m, clean=True)
     forget = sorted(s[0] + s[1] + s[3] + s[6])
     errs = 0
 
     for f in m.files():
         if f not in repo.dirstate and not os.path.isdir(m.rel(f)):
             ui.warn(_('not removing %s: file is already untracked\n')
                     % m.rel(f))
             errs = 1
 
     for f in forget:
         if ui.verbose or not m.exact(f):
             ui.status(_('removing %s\n') % m.rel(f))
 
     repo[None].remove(forget, unlink=False)
     return errs
 
 def grep(ui, repo, pattern, *pats, **opts):
     """search for a pattern in specified files and revisions
 
     Search revisions of files for a regular expression.
 
     This command behaves differently than Unix grep. It only accepts
     Python/Perl regexps. It searches repository history, not the
     working directory. It always prints the revision number in which a
     match appears.
 
     By default, grep only prints output for the first revision of a
     file in which it finds a match. To get it to print every revision
     that contains a change in match status ("-" for a match that
     becomes a non-match, or "+" for a non-match that becomes a match),
     use the --all flag.
 
     Returns 0 if a match is found, 1 otherwise.
     """
     reflags = 0
     if opts.get('ignore_case'):
         reflags |= re.I
     try:
         regexp = re.compile(pattern, reflags)
     except re.error, inst:
         ui.warn(_("grep: invalid match pattern: %s\n") % inst)
         return 1
     sep, eol = ':', '\n'
     if opts.get('print0'):
         sep = eol = '\0'
 
     getfile = util.lrucachefunc(repo.file)
 
     def matchlines(body):
         begin = 0
         linenum = 0
         while True:
             match = regexp.search(body, begin)
             if not match:
                 break
             mstart, mend = match.span()
             linenum += body.count('\n', begin, mstart) + 1
             lstart = body.rfind('\n', begin, mstart) + 1 or begin
             begin = body.find('\n', mend) + 1 or len(body)
             lend = begin - 1
             yield linenum, mstart - lstart, mend - lstart, body[lstart:lend]
 
     class linestate(object):
         def __init__(self, line, linenum, colstart, colend):
             self.line = line
             self.linenum = linenum
             self.colstart = colstart
             self.colend = colend
 
         def __hash__(self):
             return hash((self.linenum, self.line))
 
         def __eq__(self, other):
             return self.line == other.line
 
     matches = {}
     copies = {}
     def grepbody(fn, rev, body):
         matches[rev].setdefault(fn, [])
         m = matches[rev][fn]
         for lnum, cstart, cend, line in matchlines(body):
             s = linestate(line, lnum, cstart, cend)
             m.append(s)
 
     def difflinestates(a, b):
         sm = difflib.SequenceMatcher(None, a, b)
         for tag, alo, ahi, blo, bhi in sm.get_opcodes():
             if tag == 'insert':
                 for i in xrange(blo, bhi):
                     yield ('+', b[i])
             elif tag == 'delete':
                 for i in xrange(alo, ahi):
                     yield ('-', a[i])
             elif tag == 'replace':
                 for i in xrange(alo, ahi):
                     yield ('-', a[i])
                 for i in xrange(blo, bhi):
                     yield ('+', b[i])
 
     def display(fn, ctx, pstates, states):
         rev = ctx.rev()
         datefunc = ui.quiet and util.shortdate or util.datestr
         found = False
         filerevmatches = {}
         if opts.get('all'):
             iter = difflinestates(pstates, states)
         else:
             iter = [('', l) for l in states]
         for change, l in iter:
             cols = [fn, str(rev)]
             before, match, after = None, None, None
             if opts.get('line_number'):
                 cols.append(str(l.linenum))
             if opts.get('all'):
                 cols.append(change)
             if opts.get('user'):
                 cols.append(ui.shortuser(ctx.user()))
             if opts.get('date'):
                 cols.append(datefunc(ctx.date()))
             if opts.get('files_with_matches'):
                 c = (fn, rev)
                 if c in filerevmatches:
                     continue
                 filerevmatches[c] = 1
             else:
                 before = l.line[:l.colstart]
                 match = l.line[l.colstart:l.colend]
                 after = l.line[l.colend:]
             ui.write(sep.join(cols))
             if before is not None:
                 ui.write(sep + before)
                 ui.write(match, label='grep.match')
                 ui.write(after)
             ui.write(eol)
             found = True
         return found
 
     skip = {}
     revfiles = {}
     matchfn = cmdutil.match(repo, pats, opts)
     found = False
     follow = opts.get('follow')
 
     def prep(ctx, fns):
         rev = ctx.rev()
         pctx = ctx.parents()[0]
         parent = pctx.rev()
         matches.setdefault(rev, {})
         matches.setdefault(parent, {})
         files = revfiles.setdefault(rev, [])
         for fn in fns:
             flog = getfile(fn)
             try:
                 fnode = ctx.filenode(fn)
             except error.LookupError:
                 continue
 
             copied = flog.renamed(fnode)
             copy = follow and copied and copied[0]
             if copy:
                 copies.setdefault(rev, {})[fn] = copy
             if fn in skip:
                 if copy:
                     skip[copy] = True
                 continue
             files.append(fn)
 
             if fn not in matches[rev]:
                 grepbody(fn, rev, flog.read(fnode))
 
             pfn = copy or fn
             if pfn not in matches[parent]:
                 try:
                     fnode = pctx.filenode(pfn)
                     grepbody(pfn, parent, flog.read(fnode))
                 except error.LookupError:
                     pass
 
     for ctx in cmdutil.walkchangerevs(repo, matchfn, opts, prep):
         rev = ctx.rev()
         parent = ctx.parents()[0].rev()
         for fn in sorted(revfiles.get(rev, [])):
             states = matches[rev][fn]
             copy = copies.get(rev, {}).get(fn)
             if fn in skip:
                 if copy:
                     skip[copy] = True
                 continue
             pstates = matches.get(parent, {}).get(copy or fn, [])
             if pstates or states:
                 r = display(fn, ctx, pstates, states)
                 found = found or r
                 if r and not opts.get('all'):
                     skip[fn] = True
                     if copy:
                         skip[copy] = True
         del matches[rev]
         del revfiles[rev]
 
     return not found
 
 def heads(ui, repo, *branchrevs, **opts):
     """show current repository heads or show branch heads
 
     With no arguments, show all repository branch heads.
 
     Repository "heads" are changesets with no child changesets. They are
     where development generally takes place and are the usual targets
     for update and merge operations. Branch heads are changesets that have
     no child changeset on the same branch.
 
     If one or more REVs are given, only branch heads on the branches
     associated with the specified changesets are shown.
 
     If -c/--closed is specified, also show branch heads marked closed
     (see :hg:`commit --close-branch`).
 
     If STARTREV is specified, only those heads that are descendants of
     STARTREV will be displayed.
 
     If -t/--topo is specified, named branch mechanics will be ignored and only
     changesets without children will be shown.
 
     Returns 0 if matching heads are found, 1 if not.
     """
 
     if opts.get('rev'):
         start = repo.lookup(opts['rev'])
     else:
         start = None
 
     if opts.get('topo'):
         heads = [repo[h] for h in repo.heads(start)]
     else:
         heads = []
         for b, ls in repo.branchmap().iteritems():
             if start is None:
                 heads += [repo[h] for h in ls]
                 continue
             startrev = repo.changelog.rev(start)
             descendants = set(repo.changelog.descendants(startrev))
             descendants.add(startrev)
             rev = repo.changelog.rev
             heads += [repo[h] for h in ls if rev(h) in descendants]
 
     if branchrevs:
         decode, encode = encoding.fromlocal, encoding.tolocal
         branches = set(repo[decode(br)].branch() for br in branchrevs)
         heads = [h for h in heads if h.branch() in branches]
 
     if not opts.get('closed'):
         heads = [h for h in heads if not h.extra().get('close')]
 
     if opts.get('active') and branchrevs:
         dagheads = repo.heads(start)
         heads = [h for h in heads if h.node() in dagheads]
 
     if branchrevs:
         haveheads = set(h.branch() for h in heads)
         if branches - haveheads:
             headless = ', '.join(encode(b) for b in branches - haveheads)
             msg = _('no open branch heads found on branches %s')
             if opts.get('rev'):
                 msg += _(' (started at %s)' % opts['rev'])
             ui.warn((msg + '\n') % headless)
 
     if not heads:
         return 1
 
     heads = sorted(heads, key=lambda x: -x.rev())
     displayer = cmdutil.show_changeset(ui, repo, opts)
     for ctx in heads:
         displayer.show(ctx)
     displayer.close()
 
 def help_(ui, name=None, with_version=False, unknowncmd=False):
     """show help for a given topic or a help overview
 
     With no arguments, print a list of commands with short help messages.
 
     Given a topic, extension, or command name, print help for that
     topic.
 
     Returns 0 if successful.
     """
     option_lists = []
     textwidth = ui.termwidth() - 2
 
     def addglobalopts(aliases):
         if ui.verbose:
             option_lists.append((_("global options:"), globalopts))
             if name == 'shortlist':
                 option_lists.append((_('use "hg help" for the full list '
                                        'of commands'), ()))
         else:
             if name == 'shortlist':
                 msg = _('use "hg help" for the full list of commands '
                         'or "hg -v" for details')
             elif aliases:
                 msg = _('use "hg -v help%s" to show aliases and '
                         'global options') % (name and " " + name or "")
             else:
                 msg = _('use "hg -v help %s" to show global options') % name
             option_lists.append((msg, ()))
 
     def helpcmd(name):
         if with_version:
             version_(ui)
             ui.write('\n')
 
         try:
             aliases, entry = cmdutil.findcmd(name, table, strict=unknowncmd)
         except error.AmbiguousCommand, inst:
             # py3k fix: except vars can't be used outside the scope of the
             # except block, nor can be used inside a lambda. python issue4617
             prefix = inst.args[0]
             select = lambda c: c.lstrip('^').startswith(prefix)
             helplist(_('list of commands:\n\n'), select)
             return
 
         # check if it's an invalid alias and display its error if it is
         if getattr(entry[0], 'badalias', False):
             if not unknowncmd:
                 entry[0](ui)
             return
 
         # synopsis
         if len(entry) > 2:
             if entry[2].startswith('hg'):
                 ui.write("%s\n" % entry[2])
             else:
                 ui.write('hg %s %s\n' % (aliases[0], entry[2]))
         else:
             ui.write('hg %s\n' % aliases[0])
 
         # aliases
         if not ui.quiet and len(aliases) > 1:
             ui.write(_("\naliases: %s\n") % ', '.join(aliases[1:]))
 
         # description
         doc = gettext(entry[0].__doc__)
         if not doc:
             doc = _("(no help text available)")
         if hasattr(entry[0], 'definition'):  # aliased command
             if entry[0].definition.startswith('!'):  # shell alias
                 doc = _('shell alias for::\n\n    %s') % entry[0].definition[1:]
             else:
                 doc = _('alias for: hg %s\n\n%s') % (entry[0].definition, doc)
         if ui.quiet:
             doc = doc.splitlines()[0]
         keep = ui.verbose and ['verbose'] or []
         formatted, pruned = minirst.format(doc, textwidth, keep=keep)
         ui.write("\n%s\n" % formatted)
         if pruned:
             ui.write(_('\nuse "hg -v help %s" to show verbose help\n') % name)
 
         if not ui.quiet:
             # options
             if entry[1]:
                 option_lists.append((_("options:\n"), entry[1]))
 
             addglobalopts(False)
 
     def helplist(header, select=None):
         h = {}
         cmds = {}
         for c, e in table.iteritems():
             f = c.split("|", 1)[0]
             if select and not select(f):
                 continue
             if (not select and name != 'shortlist' and
                 e[0].__module__ != __name__):
                 continue
             if name == "shortlist" and not f.startswith("^"):
                 continue
             f = f.lstrip("^")
             if not ui.debugflag and f.startswith("debug"):
                 continue
             doc = e[0].__doc__
             if doc and 'DEPRECATED' in doc and not ui.verbose:
                 continue
             doc = gettext(doc)
             if not doc:
                 doc = _("(no help text available)")
             h[f] = doc.splitlines()[0].rstrip()
             cmds[f] = c.lstrip("^")
 
         if not h:
             ui.status(_('no commands defined\n'))
             return
 
         ui.status(header)
         fns = sorted(h)
         m = max(map(len, fns))
         for f in fns:
             if ui.verbose:
                 commands = cmds[f].replace("|",", ")
                 ui.write(" %s:\n      %s\n"%(commands, h[f]))
             else:
                 ui.write('%s\n' % (util.wrap(h[f], textwidth,
                                              initindent=' %-*s   ' % (m, f),
                                              hangindent=' ' * (m + 4))))
 
         if not ui.quiet:
             addglobalopts(True)
 
     def helptopic(name):
         for names, header, doc in help.helptable:
             if name in names:
                 break
         else:
             raise error.UnknownCommand(name)
 
         # description
         if not doc:
             doc = _("(no help text available)")
         if hasattr(doc, '__call__'):
             doc = doc()
 
         ui.write("%s\n\n" % header)
         ui.write("%s\n" % minirst.format(doc, textwidth, indent=4))
 
     def helpext(name):
         try:
             mod = extensions.find(name)
             doc = gettext(mod.__doc__) or _('no help text available')
         except KeyError:
             mod = None
             doc = extensions.disabledext(name)
             if not doc:
                 raise error.UnknownCommand(name)
 
         if '\n' not in doc:
             head, tail = doc, ""
         else:
             head, tail = doc.split('\n', 1)
         ui.write(_('%s extension - %s\n\n') % (name.split('.')[-1], head))
         if tail:
             ui.write(minirst.format(tail, textwidth))
             ui.status('\n\n')
 
         if mod:
             try:
                 ct = mod.cmdtable
             except AttributeError:
                 ct = {}
             modcmds = set([c.split('|', 1)[0] for c in ct])
             helplist(_('list of commands:\n\n'), modcmds.__contains__)
         else:
             ui.write(_('use "hg help extensions" for information on enabling '
                        'extensions\n'))
 
     def helpextcmd(name):
         cmd, ext, mod = extensions.disabledcmd(name, ui.config('ui', 'strict'))
         doc = gettext(mod.__doc__).splitlines()[0]
 
         msg = help.listexts(_("'%s' is provided by the following "
                               "extension:") % cmd, {ext: doc}, len(ext),
                             indent=4)
         ui.write(minirst.format(msg, textwidth))
         ui.write('\n\n')
         ui.write(_('use "hg help extensions" for information on enabling '
                    'extensions\n'))
 
     if name and name != 'shortlist':
         i = None
         if unknowncmd:
             queries = (helpextcmd,)
         else:
             queries = (helptopic, helpcmd, helpext, helpextcmd)
         for f in queries:
             try:
                 f(name)
                 i = None
                 break
             except error.UnknownCommand, inst:
                 i = inst
         if i:
             raise i
 
     else:
         # program name
         if ui.verbose or with_version:
             version_(ui)
         else:
             ui.status(_("Mercurial Distributed SCM\n"))
         ui.status('\n')
 
         # list of commands
         if name == "shortlist":
             header = _('basic commands:\n\n')
         else:
             header = _('list of commands:\n\n')
 
         helplist(header)
         if name != 'shortlist':
             exts, maxlength = extensions.enabled()
             text = help.listexts(_('enabled extensions:'), exts, maxlength)
             if text:
                 ui.write("\n%s\n" % minirst.format(text, textwidth))
 
     # list all option lists
     opt_output = []
     multioccur = False
     for title, options in option_lists:
         opt_output.append(("\n%s" % title, None))
         for option in options:
             if len(option) == 5:
                 shortopt, longopt, default, desc, optlabel = option
             else:
                 shortopt, longopt, default, desc = option
                 optlabel = _("VALUE") # default label
 
             if _("DEPRECATED") in desc and not ui.verbose:
                 continue
             if isinstance(default, list):
                 numqualifier = " %s [+]" % optlabel
                 multioccur = True
             elif (default is not None) and not isinstance(default, bool):
                 numqualifier = " %s" % optlabel
             else:
                 numqualifier = ""
             opt_output.append(("%2s%s" %
                                (shortopt and "-%s" % shortopt,
                                 longopt and " --%s%s" %
                                 (longopt, numqualifier)),
                                "%s%s" % (desc,
                                          default
                                          and _(" (default: %s)") % default
                                          or "")))
     if multioccur:
         msg = _("\n[+] marked option can be specified multiple times")
         if ui.verbose and name != 'shortlist':
             opt_output.append((msg, None))
         else:
             opt_output.insert(-1, (msg, None))
 
     if not name:
         ui.write(_("\nadditional help topics:\n\n"))
         topics = []
         for names, header, doc in help.helptable:
             topics.append((sorted(names, key=len, reverse=True)[0], header))
         topics_len = max([len(s[0]) for s in topics])
         for t, desc in topics:
             ui.write(" %-*s  %s\n" % (topics_len, t, desc))
 
     if opt_output:
         colwidth = encoding.colwidth
         # normalize: (opt or message, desc or None, width of opt)
         entries = [desc and (opt, desc, colwidth(opt)) or (opt, None, 0)
                    for opt, desc in opt_output]
         hanging = max([e[2] for e in entries])
         for opt, desc, width in entries:
             if desc:
                 initindent = ' %s%s  ' % (opt, ' ' * (hanging - width))
                 hangindent = ' ' * (hanging + 3)
                 ui.write('%s\n' % (util.wrap(desc, textwidth,
                                              initindent=initindent,
                                              hangindent=hangindent)))
             else:
                 ui.write("%s\n" % opt)
 
 def identify(ui, repo, source=None,
              rev=None, num=None, id=None, branch=None, tags=None):
     """identify the working copy or specified revision
 
     With no revision, print a summary of the current state of the
     repository.
 
     Specifying a path to a repository root or Mercurial bundle will
     cause lookup to operate on that repository/bundle.
 
     This summary identifies the repository state using one or two
     parent hash identifiers, followed by a "+" if there are
     uncommitted changes in the working directory, a list of tags for
     this revision and a branch name for non-default branches.
 
     Returns 0 if successful.
     """
 
     if not repo and not source:
         raise util.Abort(_("there is no Mercurial repository here "
                            "(.hg not found)"))
 
     hexfunc = ui.debugflag and hex or short
     default = not (num or id or branch or tags)
     output = []
 
     revs = []
     if source:
         source, branches = hg.parseurl(ui.expandpath(source))
         repo = hg.repository(ui, source)
         revs, checkout = hg.addbranchrevs(repo, repo, branches, None)
 
     if not repo.local():
         if not rev and revs:
             rev = revs[0]
         if not rev:
             rev = "tip"
         if num or branch or tags:
             raise util.Abort(
                 "can't query remote revision number, branch, or tags")
         output = [hexfunc(repo.lookup(rev))]
     elif not rev:
         ctx = repo[None]
         parents = ctx.parents()
         changed = False
         if default or id or num:
             changed = util.any(repo.status())
         if default or id:
             output = ["%s%s" % ('+'.join([hexfunc(p.node()) for p in parents]),
                                 (changed) and "+" or "")]
         if num:
             output.append("%s%s" % ('+'.join([str(p.rev()) for p in parents]),
                                     (changed) and "+" or ""))
     else:
         ctx = repo[rev]
         if default or id:
             output = [hexfunc(ctx.node())]
         if num:
             output.append(str(ctx.rev()))
 
     if repo.local() and default and not ui.quiet:
         b = encoding.tolocal(ctx.branch())
         if b != 'default':
             output.append("(%s)" % b)
 
         # multiple tags for a single parent separated by '/'
         t = "/".join(ctx.tags())
         if t:
             output.append(t)
 
     if branch:
         output.append(encoding.tolocal(ctx.branch()))
 
     if tags:
         output.extend(ctx.tags())
 
     ui.write("%s\n" % ' '.join(output))
 
 def import_(ui, repo, patch1, *patches, **opts):
     """import an ordered set of patches
 
     Import a list of patches and commit them individually (unless
     --no-commit is specified).
 
     If there are outstanding changes in the working directory, import
     will abort unless given the -f/--force flag.
 
     You can import a patch straight from a mail message. Even patches
     as attachments work (to use the body part, it must have type
     text/plain or text/x-patch). From and Subject headers of email
     message are used as default committer and commit message. All
     text/plain body parts before first diff are added to commit
     message.
 
     If the imported patch was generated by :hg:`export`, user and
     description from patch override values from message headers and
     body. Values given on command line with -m/--message and -u/--user
     override these.
 
     If --exact is specified, import will set the working directory to
     the parent of each patch before applying it, and will abort if the
     resulting changeset has a different ID than the one recorded in
     the patch. This may happen due to character set problems or other
     deficiencies in the text patch format.
 
     With -s/--similarity, hg will attempt to discover renames and
     copies in the patch in the same way as 'addremove'.
 
     To read a patch from standard input, use "-" as the patch name. If
     a URL is specified, the patch will be downloaded from it.
     See :hg:`help dates` for a list of formats valid for -d/--date.
 
     Returns 0 on success.
     """
     patches = (patch1,) + patches
 
     date = opts.get('date')
     if date:
         opts['date'] = util.parsedate(date)
 
     try:
         sim = float(opts.get('similarity') or 0)
     except ValueError:
         raise util.Abort(_('similarity must be a number'))
     if sim < 0 or sim > 100:
         raise util.Abort(_('similarity must be between 0 and 100'))
 
     if opts.get('exact') or not opts.get('force'):
         cmdutil.bail_if_changed(repo)
 
     d = opts["base"]
     strip = opts["strip"]
     wlock = lock = None
 
     def tryone(ui, hunk):
         tmpname, message, user, date, branch, nodeid, p1, p2 = \
             patch.extract(ui, hunk)
 
         if not tmpname:
             return None
         commitid = _('to working directory')
 
         try:
             cmdline_message = cmdutil.logmessage(opts)
             if cmdline_message:
                 # pickup the cmdline msg
                 message = cmdline_message
             elif message:
                 # pickup the patch msg
                 message = message.strip()
             else:
                 # launch the editor
                 message = None
             ui.debug('message:\n%s\n' % message)
 
             wp = repo.parents()
             if opts.get('exact'):
                 if not nodeid or not p1:
                     raise util.Abort(_('not a Mercurial patch'))
                 p1 = repo.lookup(p1)
                 p2 = repo.lookup(p2 or hex(nullid))
 
                 if p1 != wp[0].node():
                     hg.clean(repo, p1)
                 repo.dirstate.setparents(p1, p2)
             elif p2:
                 try:
                     p1 = repo.lookup(p1)
                     p2 = repo.lookup(p2)
                     if p1 == wp[0].node():
                         repo.dirstate.setparents(p1, p2)
                 except error.RepoError:
                     pass
             if opts.get('exact') or opts.get('import_branch'):
                 repo.dirstate.setbranch(branch or 'default')
 
             files = {}
             try:
                 patch.patch(tmpname, ui, strip=strip, cwd=repo.root,
                             files=files, eolmode=None)
             finally:
                 files = cmdutil.updatedir(ui, repo, files,
                                           similarity=sim / 100.0)
             if not opts.get('no_commit'):
                 if opts.get('exact'):
                     m = None
                 else:
                     m = cmdutil.matchfiles(repo, files or [])
                 n = repo.commit(message, opts.get('user') or user,
                                 opts.get('date') or date, match=m,
                                 editor=cmdutil.commiteditor)
                 if opts.get('exact'):
                     if hex(n) != nodeid:
                         repo.rollback()
                         raise util.Abort(_('patch is damaged'
                                            ' or loses information'))
                 # Force a dirstate write so that the next transaction
                 # backups an up-do-date file.
                 repo.dirstate.write()
                 if n:
                     commitid = short(n)
 
             return commitid
         finally:
             os.unlink(tmpname)
 
     try:
         wlock = repo.wlock()
         lock = repo.lock()
         lastcommit = None
         for p in patches:
             pf = os.path.join(d, p)
 
             if pf == '-':
                 ui.status(_("applying patch from stdin\n"))
                 pf = sys.stdin
             else:
                 ui.status(_("applying %s\n") % p)
                 pf = url.open(ui, pf)
 
             haspatch = False
             for hunk in patch.split(pf):
                 commitid = tryone(ui, hunk)
                 if commitid:
                     haspatch = True
                     if lastcommit:
                         ui.status(_('applied %s\n') % lastcommit)
                     lastcommit = commitid
 
             if not haspatch:
                 raise util.Abort(_('no diffs found'))
 
     finally:
         release(lock, wlock)
 
 def incoming(ui, repo, source="default", **opts):
     """show new changesets found in source
 
     Show new changesets found in the specified path/URL or the default
     pull location. These are the changesets that would have been pulled
     if a pull at the time you issued this command.
 
     For remote repository, using --bundle avoids downloading the
     changesets twice if the incoming is followed by a pull.
 
     See pull for valid source format details.
 
     Returns 0 if there are incoming changes, 1 otherwise.
     """
     if opts.get('bundle') and opts.get('subrepos'):
         raise util.Abort(_('cannot combine --bundle and --subrepos'))
 
     ret = hg.incoming(ui, repo, source, opts)
     return ret
 
 def init(ui, dest=".", **opts):
     """create a new repository in the given directory
 
     Initialize a new repository in the given directory. If the given
     directory does not exist, it will be created.
 
     If no directory is given, the current directory is used.
 
     It is possible to specify an ``ssh://`` URL as the destination.
     See :hg:`help urls` for more information.
 
     Returns 0 on success.
     """
     hg.repository(hg.remoteui(ui, opts), ui.expandpath(dest), create=1)
 
 def locate(ui, repo, *pats, **opts):
     """locate files matching specific patterns
 
     Print files under Mercurial control in the working directory whose
     names match the given patterns.
 
     By default, this command searches all directories in the working
     directory. To search just the current directory and its
     subdirectories, use "--include .".
 
     If no patterns are given to match, this command prints the names
     of all files under Mercurial control in the working directory.
 
     If you want to feed the output of this command into the "xargs"
     command, use the -0 option to both this command and "xargs". This
     will avoid the problem of "xargs" treating single filenames that
     contain whitespace as multiple filenames.
 
     Returns 0 if a match is found, 1 otherwise.
     """
     end = opts.get('print0') and '\0' or '\n'
     rev = opts.get('rev') or None
 
     ret = 1
     m = cmdutil.match(repo, pats, opts, default='relglob')
     m.bad = lambda x, y: False
     for abs in repo[rev].walk(m):
         if not rev and abs not in repo.dirstate:
             continue
         if opts.get('fullpath'):
             ui.write(repo.wjoin(abs), end)
         else:
             ui.write(((pats and m.rel(abs)) or abs), end)
         ret = 0
 
     return ret
 
 def log(ui, repo, *pats, **opts):
     """show revision history of entire repository or files
 
     Print the revision history of the specified files or the entire
     project.
 
     File history is shown without following rename or copy history of
     files. Use -f/--follow with a filename to follow history across
     renames and copies. --follow without a filename will only show
     ancestors or descendants of the starting revision. --follow-first
     only follows the first parent of merge revisions.
 
     If no revision range is specified, the default is tip:0 unless
     --follow is set, in which case the working directory parent is
     used as the starting revision. You can specify a revision set for
     log, see :hg:`help revsets` for more information.
 
     See :hg:`help dates` for a list of formats valid for -d/--date.
 
     By default this command prints revision number and changeset id,
     tags, non-trivial parents, user, date and time, and a summary for
     each commit. When the -v/--verbose switch is used, the list of
     changed files and full commit message are shown.
 
     .. note::
        log -p/--patch may generate unexpected diff output for merge
        changesets, as it will only compare the merge changeset against
        its first parent. Also, only files different from BOTH parents
        will appear in files:.
 
     Returns 0 on success.
     """
 
     matchfn = cmdutil.match(repo, pats, opts)
     limit = cmdutil.loglimit(opts)
     count = 0
 
     endrev = None
     if opts.get('copies') and opts.get('rev'):
         endrev = max(cmdutil.revrange(repo, opts.get('rev'))) + 1
 
     df = False
     if opts["date"]:
         df = util.matchdate(opts["date"])
 
     branches = opts.get('branch', []) + opts.get('only_branch', [])
     opts['branch'] = [repo.lookupbranch(b) for b in branches]
 
     displayer = cmdutil.show_changeset(ui, repo, opts, True)
     def prep(ctx, fns):
         rev = ctx.rev()
         parents = [p for p in repo.changelog.parentrevs(rev)
                    if p != nullrev]
         if opts.get('no_merges') and len(parents) == 2:
             return
         if opts.get('only_merges') and len(parents) != 2:
             return
         if opts.get('branch') and ctx.branch() not in opts['branch']:
             return
         if df and not df(ctx.date()[0]):
             return
         if opts['user'] and not [k for k in opts['user'] if k in ctx.user()]:
             return
         if opts.get('keyword'):
             for k in [kw.lower() for kw in opts['keyword']]:
                 if (k in ctx.user().lower() or
                     k in ctx.description().lower() or
                     k in " ".join(ctx.files()).lower()):
                     break
             else:
                 return
 
         copies = None
         if opts.get('copies') and rev:
             copies = []
             getrenamed = templatekw.getrenamedfn(repo, endrev=endrev)
             for fn in ctx.files():
                 rename = getrenamed(fn, rev)
                 if rename:
                     copies.append((fn, rename[0]))
 
         revmatchfn = None
         if opts.get('patch') or opts.get('stat'):
             if opts.get('follow') or opts.get('follow_first'):
                 # note: this might be wrong when following through merges
                 revmatchfn = cmdutil.match(repo, fns, default='path')
             else:
                 revmatchfn = matchfn
 
         displayer.show(ctx, copies=copies, matchfn=revmatchfn)
 
     for ctx in cmdutil.walkchangerevs(repo, matchfn, opts, prep):
         if count == limit:
             break
         if displayer.flush(ctx.rev()):
             count += 1
     displayer.close()
 
 def manifest(ui, repo, node=None, rev=None):
     """output the current or given revision of the project manifest
 
     Print a list of version controlled files for the given revision.
     If no revision is given, the first parent of the working directory
     is used, or the null revision if no revision is checked out.
 
     With -v, print file permissions, symlink and executable bits.
     With --debug, print file revision hashes.
 
     Returns 0 on success.
     """
 
     if rev and node:
         raise util.Abort(_("please specify just one revision"))
 
     if not node:
         node = rev
 
     decor = {'l':'644 @ ', 'x':'755 * ', '':'644   '}
     ctx = repo[node]
     for f in ctx:
         if ui.debugflag:
             ui.write("%40s " % hex(ctx.manifest()[f]))
         if ui.verbose:
             ui.write(decor[ctx.flags(f)])
         ui.write("%s\n" % f)
 
 def merge(ui, repo, node=None, **opts):
     """merge working directory with another revision
 
     The current working directory is updated with all changes made in
     the requested revision since the last common predecessor revision.
 
     Files that changed between either parent are marked as changed for
     the next commit and a commit must be performed before any further
     updates to the repository are allowed. The next commit will have
     two parents.
 
     If no revision is specified, the working directory's parent is a
     head revision, and the current branch contains exactly one other
     head, the other head is merged with by default. Otherwise, an
     explicit revision with which to merge with must be provided.
 
     To undo an uncommitted merge, use :hg:`update --clean .` which
     will check out a clean copy of the original merge parent, losing
     all changes.
 
     Returns 0 on success, 1 if there are unresolved files.
     """
 
     if opts.get('rev') and node:
         raise util.Abort(_("please specify just one revision"))
     if not node:
         node = opts.get('rev')
 
     if not node:
         branch = repo.changectx(None).branch()
         bheads = repo.branchheads(branch)
         if len(bheads) > 2:
             raise util.Abort(_(
                 'branch \'%s\' has %d heads - '
                 'please merge with an explicit rev\n'
                 '(run \'hg heads .\' to see heads)')
                 % (branch, len(bheads)))
 
         parent = repo.dirstate.parents()[0]
         if len(bheads) == 1:
             if len(repo.heads()) > 1:
                 raise util.Abort(_(
                     'branch \'%s\' has one head - '
                     'please merge with an explicit rev\n'
                     '(run \'hg heads\' to see all heads)')
                     % branch)
             msg = _('there is nothing to merge')
             if parent != repo.lookup(repo[None].branch()):
                 msg = _('%s - use "hg update" instead') % msg
             raise util.Abort(msg)
 
         if parent not in bheads:
             raise util.Abort(_('working dir not at a head rev - '
                                'use "hg update" or merge with an explicit rev'))
         node = parent == bheads[0] and bheads[-1] or bheads[0]
 
     if opts.get('preview'):
         # find nodes that are ancestors of p2 but not of p1
         p1 = repo.lookup('.')
         p2 = repo.lookup(node)
         nodes = repo.changelog.findmissing(common=[p1], heads=[p2])
 
         displayer = cmdutil.show_changeset(ui, repo, opts)
         for node in nodes:
             displayer.show(repo[node])
         displayer.close()
         return 0
 
     return hg.merge(repo, node, force=opts.get('force'))
 
 def outgoing(ui, repo, dest=None, **opts):
     """show changesets not found in the destination
 
     Show changesets not found in the specified destination repository
     or the default push location. These are the changesets that would
     be pushed if a push was requested.
 
     See pull for details of valid destination formats.
 
     Returns 0 if there are outgoing changes, 1 otherwise.
     """
     ret = hg.outgoing(ui, repo, dest, opts)
     return ret
 
 def parents(ui, repo, file_=None, **opts):
     """show the parents of the working directory or revision
 
     Print the working directory's parent revisions. If a revision is
     given via -r/--rev, the parent of that revision will be printed.
     If a file argument is given, the revision in which the file was
     last changed (before the working directory revision or the
     argument to --rev if given) is printed.
 
     Returns 0 on success.
     """
     rev = opts.get('rev')
     if rev:
         ctx = repo[rev]
     else:
         ctx = repo[None]
 
     if file_:
         m = cmdutil.match(repo, (file_,), opts)
         if m.anypats() or len(m.files()) != 1:
             raise util.Abort(_('can only specify an explicit filename'))
         file_ = m.files()[0]
         filenodes = []
         for cp in ctx.parents():
             if not cp:
                 continue
             try:
                 filenodes.append(cp.filenode(file_))
             except error.LookupError:
                 pass
         if not filenodes:
             raise util.Abort(_("'%s' not found in manifest!") % file_)
         fl = repo.file(file_)
         p = [repo.lookup(fl.linkrev(fl.rev(fn))) for fn in filenodes]
     else:
         p = [cp.node() for cp in ctx.parents()]
 
     displayer = cmdutil.show_changeset(ui, repo, opts)
     for n in p:
         if n != nullid:
             displayer.show(repo[n])
     displayer.close()
 
 def paths(ui, repo, search=None):
     """show aliases for remote repositories
 
     Show definition of symbolic path name NAME. If no name is given,
     show definition of all available names.
 
     Path names are defined in the [paths] section of your
     configuration file and in ``/etc/mercurial/hgrc``. If run inside a
     repository, ``.hg/hgrc`` is used, too.
 
     The path names ``default`` and ``default-push`` have a special
     meaning.  When performing a push or pull operation, they are used
     as fallbacks if no location is specified on the command-line.
     When ``default-push`` is set, it will be used for push and
     ``default`` will be used for pull; otherwise ``default`` is used
     as the fallback for both.  When cloning a repository, the clone
     source is written as ``default`` in ``.hg/hgrc``.  Note that
     ``default`` and ``default-push`` apply to all inbound (e.g.
     :hg:`incoming`) and outbound (e.g. :hg:`outgoing`, :hg:`email` and
     :hg:`bundle`) operations.
 
     See :hg:`help urls` for more information.
 
     Returns 0 on success.
     """
     if search:
         for name, path in ui.configitems("paths"):
             if name == search:
                 ui.write("%s\n" % url.hidepassword(path))
                 return
         ui.warn(_("not found!\n"))
         return 1
     else:
         for name, path in ui.configitems("paths"):
             ui.write("%s = %s\n" % (name, url.hidepassword(path)))
 
 def postincoming(ui, repo, modheads, optupdate, checkout):
     if modheads == 0:
         return
     if optupdate:
         if (modheads <= 1 or len(repo.branchheads()) == 1) or checkout:
             return hg.update(repo, checkout)
         else:
             ui.status(_("not updating, since new heads added\n"))
     if modheads > 1:
         ui.status(_("(run 'hg heads' to see heads, 'hg merge' to merge)\n"))
     else:
         ui.status(_("(run 'hg update' to get a working copy)\n"))
 
 def pull(ui, repo, source="default", **opts):
     """pull changes from the specified source
 
     Pull changes from a remote repository to a local one.
 
     This finds all changes from the repository at the specified path
     or URL and adds them to a local repository (the current one unless
     -R is specified). By default, this does not update the copy of the
     project in the working directory.
 
     Use :hg:`incoming` if you want to see what would have been added
     by a pull at the time you issued this command. If you then decide
     to add those changes to the repository, you should use :hg:`pull
     -r X` where ``X`` is the last changeset listed by :hg:`incoming`.
 
     If SOURCE is omitted, the 'default' path will be used.
     See :hg:`help urls` for more information.
 
     Returns 0 on success, 1 if an update had unresolved files.
     """
     source, branches = hg.parseurl(ui.expandpath(source), opts.get('branch'))
     other = hg.repository(hg.remoteui(repo, opts), source)
     ui.status(_('pulling from %s\n') % url.hidepassword(source))
     revs, checkout = hg.addbranchrevs(repo, other, branches, opts.get('rev'))
     if revs:
         try:
             revs = [other.lookup(rev) for rev in revs]
         except error.CapabilityError:
             err = _("other repository doesn't support revision lookup, "
                     "so a rev cannot be specified.")
             raise util.Abort(err)
 
     modheads = repo.pull(other, heads=revs, force=opts.get('force'))
     if checkout:
         checkout = str(repo.changelog.rev(other.lookup(checkout)))
     return postincoming(ui, repo, modheads, opts.get('update'), checkout)
 
 def push(ui, repo, dest=None, **opts):
     """push changes to the specified destination
 
     Push changesets from the local repository to the specified
     destination.
 
     This operation is symmetrical to pull: it is identical to a pull
     in the destination repository from the current one.
 
     By default, push will not allow creation of new heads at the
     destination, since multiple heads would make it unclear which head
     to use. In this situation, it is recommended to pull and merge
     before pushing.
 
     Use --new-branch if you want to allow push to create a new named
     branch that is not present at the destination. This allows you to
     only create a new branch without forcing other changes.
 
     Use -f/--force to override the default behavior and push all
     changesets on all branches.
 
     If -r/--rev is used, the specified revision and all its ancestors
     will be pushed to the remote repository.
 
     Please see :hg:`help urls` for important details about ``ssh://``
     URLs. If DESTINATION is omitted, a default path will be used.
 
     Returns 0 if push was successful, 1 if nothing to push.
     """
     dest = ui.expandpath(dest or 'default-push', dest or 'default')
     dest, branches = hg.parseurl(dest, opts.get('branch'))
     revs, checkout = hg.addbranchrevs(repo, repo, branches, opts.get('rev'))
     other = hg.repository(hg.remoteui(repo, opts), dest)
     ui.status(_('pushing to %s\n') % url.hidepassword(dest))
     if revs:
         revs = [repo.lookup(rev) for rev in revs]
 
     # push subrepos depth-first for coherent ordering
     c = repo['']
     subs = c.substate # only repos that are committed
     for s in sorted(subs):
         if not c.sub(s).push(opts.get('force')):
             return False
 
     r = repo.push(other, opts.get('force'), revs=revs,
                   newbranch=opts.get('new_branch'))
     return r == 0
 
 def recover(ui, repo):
     """roll back an interrupted transaction
 
     Recover from an interrupted commit or pull.
 
     This command tries to fix the repository status after an
     interrupted operation. It should only be necessary when Mercurial
     suggests it.
 
     Returns 0 if successful, 1 if nothing to recover or verify fails.
     """
     if repo.recover():
         return hg.verify(repo)
     return 1
 
 def remove(ui, repo, *pats, **opts):
     """remove the specified files on the next commit
 
     Schedule the indicated files for removal from the repository.
 
     This only removes files from the current branch, not from the
     entire project history. -A/--after can be used to remove only
     files that have already been deleted, -f/--force can be used to
     force deletion, and -Af can be used to remove files from the next
     revision without deleting them from the working directory.
 
     The following table details the behavior of remove for different
     file states (columns) and option combinations (rows). The file
     states are Added [A], Clean [C], Modified [M] and Missing [!] (as
     reported by :hg:`status`). The actions are Warn, Remove (from
     branch) and Delete (from disk)::
 
              A  C  M  !
       none   W  RD W  R
       -f     R  RD RD R
       -A     W  W  W  R
       -Af    R  R  R  R
 
     This command schedules the files to be removed at the next commit.
     To undo a remove before that, see :hg:`revert`.
 
     Returns 0 on success, 1 if any warnings encountered.
     """
 
     ret = 0
     after, force = opts.get('after'), opts.get('force')
     if not pats and not after:
         raise util.Abort(_('no files specified'))
 
     m = cmdutil.match(repo, pats, opts)
     s = repo.status(match=m, clean=True)
     modified, added, deleted, clean = s[0], s[1], s[3], s[6]
 
     for f in m.files():
         if f not in repo.dirstate and not os.path.isdir(m.rel(f)):
             ui.warn(_('not removing %s: file is untracked\n') % m.rel(f))
             ret = 1
 
     if force:
         remove, forget = modified + deleted + clean, added
     elif after:
         remove, forget = deleted, []
         for f in modified + added + clean:
             ui.warn(_('not removing %s: file still exists (use -f'
                       ' to force removal)\n') % m.rel(f))
             ret = 1
     else:
         remove, forget = deleted + clean, []
         for f in modified:
             ui.warn(_('not removing %s: file is modified (use -f'
                       ' to force removal)\n') % m.rel(f))
             ret = 1
         for f in added:
             ui.warn(_('not removing %s: file has been marked for add (use -f'
                       ' to force removal)\n') % m.rel(f))
             ret = 1
 
     for f in sorted(remove + forget):
         if ui.verbose or not m.exact(f):
             ui.status(_('removing %s\n') % m.rel(f))
 
     repo[None].forget(forget)
     repo[None].remove(remove, unlink=not after)
     return ret
 
 def rename(ui, repo, *pats, **opts):
     """rename files; equivalent of copy + remove
 
     Mark dest as copies of sources; mark sources for deletion. If dest
     is a directory, copies are put in that directory. If dest is a
     file, there can only be one source.
 
     By default, this command copies the contents of files as they
     exist in the working directory. If invoked with -A/--after, the
     operation is recorded, but no copying is performed.
 
     This command takes effect at the next commit. To undo a rename
     before that, see :hg:`revert`.
 
     Returns 0 on success, 1 if errors are encountered.
     """
     wlock = repo.wlock(False)
     try:
         return cmdutil.copy(ui, repo, pats, opts, rename=True)
     finally:
         wlock.release()
 
 def resolve(ui, repo, *pats, **opts):
     """redo merges or set/view the merge status of files
 
     Merges with unresolved conflicts are often the result of
     non-interactive merging using the ``internal:merge`` configuration
     setting, or a command-line merge tool like ``diff3``. The resolve
     command is used to manage the files involved in a merge, after
     :hg:`merge` has been run, and before :hg:`commit` is run (i.e. the
     working directory must have two parents).
 
     The resolve command can be used in the following ways:
 
     - :hg:`resolve FILE...`: attempt to re-merge the specified files,
       discarding any previous merge attempts. Re-merging is not
       performed for files already marked as resolved. Use ``--all/-a``
       to selects all unresolved files.
 
     - :hg:`resolve -m [FILE]`: mark a file as having been resolved
       (e.g. after having manually fixed-up the files). The default is
       to mark all unresolved files.
 
     - :hg:`resolve -u [FILE]...`: mark a file as unresolved. The
       default is to mark all resolved files.
 
     - :hg:`resolve -l`: list files which had or still have conflicts.
       In the printed list, ``U`` = unresolved and ``R`` = resolved.
 
     Note that Mercurial will not let you commit files with unresolved
     merge conflicts. You must use :hg:`resolve -m ...` before you can
     commit after a conflicting merge.
 
     Returns 0 on success, 1 if any files fail a resolve attempt.
     """
 
     all, mark, unmark, show, nostatus = \
         [opts.get(o) for o in 'all mark unmark list no_status'.split()]
 
     if (show and (mark or unmark)) or (mark and unmark):
         raise util.Abort(_("too many options specified"))
     if pats and all:
         raise util.Abort(_("can't specify --all and patterns"))
     if not (all or pats or show or mark or unmark):
         raise util.Abort(_('no files or directories specified; '
                            'use --all to remerge all files'))
 
     ms = mergemod.mergestate(repo)
     m = cmdutil.match(repo, pats, opts)
     ret = 0
 
     for f in ms:
         if m(f):
             if show:
                 if nostatus:
                     ui.write("%s\n" % f)
                 else:
                     ui.write("%s %s\n" % (ms[f].upper(), f),
                              label='resolve.' +
                              {'u': 'unresolved', 'r': 'resolved'}[ms[f]])
             elif mark:
                 ms.mark(f, "r")
             elif unmark:
                 ms.mark(f, "u")
             else:
                 wctx = repo[None]
                 mctx = wctx.parents()[-1]
 
                 # backup pre-resolve (merge uses .orig for its own purposes)
                 a = repo.wjoin(f)
                 util.copyfile(a, a + ".resolve")
 
                 # resolve file
                 if ms.resolve(f, wctx, mctx):
                     ret = 1
 
                 # replace filemerge's .orig file with our resolve file
                 util.rename(a + ".resolve", a + ".orig")
 
     ms.commit()
     return ret
 
 def revert(ui, repo, *pats, **opts):
     """restore individual files or directories to an earlier state
 
     .. note::
        This command is most likely not what you are looking for.
        revert will partially overwrite content in the working
        directory without changing the working directory parents. Use
        :hg:`update -r rev` to check out earlier revisions, or
        :hg:`update --clean .` to undo a merge which has added another
        parent.
 
     With no revision specified, revert the named files or directories
     to the contents they had in the parent of the working directory.
     This restores the contents of the affected files to an unmodified
     state and unschedules adds, removes, copies, and renames. If the
     working directory has two parents, you must explicitly specify a
     revision.
 
     Using the -r/--rev option, revert the given files or directories
     to their contents as of a specific revision. This can be helpful
     to "roll back" some or all of an earlier change. See :hg:`help
     dates` for a list of formats valid for -d/--date.
 
     Revert modifies the working directory. It does not commit any
     changes, or change the parent of the working directory. If you
     revert to a revision other than the parent of the working
     directory, the reverted files will thus appear modified
     afterwards.
 
     If a file has been deleted, it is restored. If the executable mode
     of a file was changed, it is reset.
 
     If names are given, all files matching the names are reverted.
     If no arguments are given, no files are reverted.
 
     Modified files are saved with a .orig suffix before reverting.
     To disable these backups, use --no-backup.
 
     Returns 0 on success.
     """
 
     if opts.get("date"):
         if opts.get("rev"):
             raise util.Abort(_("you can't specify a revision and a date"))
         opts["rev"] = cmdutil.finddate(ui, repo, opts["date"])
 
     if not pats and not opts.get('all'):
         raise util.Abort(_('no files or directories specified; '
                            'use --all to revert the whole repo'))
 
     parent, p2 = repo.dirstate.parents()
     if not opts.get('rev') and p2 != nullid:
         raise util.Abort(_('uncommitted merge - please provide a '
                            'specific revision'))
     ctx = repo[opts.get('rev')]
     node = ctx.node()
     mf = ctx.manifest()
     if node == parent:
         pmf = mf
     else:
         pmf = None
 
     # need all matching names in dirstate and manifest of target rev,
     # so have to walk both. do not print errors if files exist in one
     # but not other.
 
     names = {}
 
     wlock = repo.wlock()
     try:
         # walk dirstate.
 
         m = cmdutil.match(repo, pats, opts)
         m.bad = lambda x, y: False
         for abs in repo.walk(m):
             names[abs] = m.rel(abs), m.exact(abs)
 
         # walk target manifest.
 
         def badfn(path, msg):
             if path in names:
                 return
             path_ = path + '/'
             for f in names:
                 if f.startswith(path_):
                     return
             ui.warn("%s: %s\n" % (m.rel(path), msg))
 
         m = cmdutil.match(repo, pats, opts)
         m.bad = badfn
         for abs in repo[node].walk(m):
             if abs not in names:
                 names[abs] = m.rel(abs), m.exact(abs)
 
         m = cmdutil.matchfiles(repo, names)
         changes = repo.status(match=m)[:4]
         modified, added, removed, deleted = map(set, changes)
 
         # if f is a rename, also revert the source
         cwd = repo.getcwd()
         for f in added:
             src = repo.dirstate.copied(f)
             if src and src not in names and repo.dirstate[src] == 'r':
                 removed.add(src)
                 names[src] = (repo.pathto(src, cwd), True)
 
         def removeforget(abs):
             if repo.dirstate[abs] == 'a':
                 return _('forgetting %s\n')
             return _('removing %s\n')
 
         revert = ([], _('reverting %s\n'))
         add = ([], _('adding %s\n'))
         remove = ([], removeforget)
         undelete = ([], _('undeleting %s\n'))
 
         disptable = (
             # dispatch table:
             #   file state
             #   action if in target manifest
             #   action if not in target manifest
             #   make backup if in target manifest
             #   make backup if not in target manifest
             (modified, revert, remove, True, True),
             (added, revert, remove, True, False),
             (removed, undelete, None, False, False),
             (deleted, revert, remove, False, False),
             )
 
         for abs, (rel, exact) in sorted(names.items()):
             mfentry = mf.get(abs)
             target = repo.wjoin(abs)
             def handle(xlist, dobackup):
                 xlist[0].append(abs)
                 if (dobackup and not opts.get('no_backup') and
                     os.path.lexists(target)):
                     bakname = "%s.orig" % rel
                     ui.note(_('saving current version of %s as %s\n') %
                             (rel, bakname))
                     if not opts.get('dry_run'):
                         util.rename(target, bakname)
                 if ui.verbose or not exact:
                     msg = xlist[1]
                     if not isinstance(msg, basestring):
                         msg = msg(abs)
                     ui.status(msg % rel)
             for table, hitlist, misslist, backuphit, backupmiss in disptable:
                 if abs not in table:
                     continue
                 # file has changed in dirstate
                 if mfentry:
                     handle(hitlist, backuphit)
                 elif misslist is not None:
                     handle(misslist, backupmiss)
                 break
             else:
                 if abs not in repo.dirstate:
                     if mfentry:
                         handle(add, True)
                     elif exact:
                         ui.warn(_('file not managed: %s\n') % rel)
                     continue
                 # file has not changed in dirstate
                 if node == parent:
                     if exact:
                         ui.warn(_('no changes needed to %s\n') % rel)
                     continue
                 if pmf is None:
                     # only need parent manifest in this unlikely case,
                     # so do not read by default
                     pmf = repo[parent].manifest()
                 if abs in pmf:
                     if mfentry:
                         # if version of file is same in parent and target
                         # manifests, do nothing
                         if (pmf[abs] != mfentry or
                             pmf.flags(abs) != mf.flags(abs)):
                             handle(revert, False)
                     else:
                         handle(remove, False)
 
         if not opts.get('dry_run'):
             def checkout(f):
                 fc = ctx[f]
                 repo.wwrite(f, fc.data(), fc.flags())
 
             audit_path = util.path_auditor(repo.root)
             for f in remove[0]:
                 if repo.dirstate[f] == 'a':
                     repo.dirstate.forget(f)
                     continue
                 audit_path(f)
                 try:
                     util.unlink(repo.wjoin(f))
                 except OSError:
                     pass
                 repo.dirstate.remove(f)
 
             normal = None
             if node == parent:
                 # We're reverting to our parent. If possible, we'd like status
                 # to report the file as clean. We have to use normallookup for
                 # merges to avoid losing information about merged/dirty files.
                 if p2 != nullid:
                     normal = repo.dirstate.normallookup
                 else:
                     normal = repo.dirstate.normal
             for f in revert[0]:
                 checkout(f)
                 if normal:
                     normal(f)
 
             for f in add[0]:
                 checkout(f)
                 repo.dirstate.add(f)
 
             normal = repo.dirstate.normallookup
             if node == parent and p2 == nullid:
                 normal = repo.dirstate.normal
             for f in undelete[0]:
                 checkout(f)
                 normal(f)
 
     finally:
         wlock.release()
 
 def rollback(ui, repo, **opts):
     """roll back the last transaction (dangerous)
 
     This command should be used with care. There is only one level of
     rollback, and there is no way to undo a rollback. It will also
     restore the dirstate at the time of the last transaction, losing
     any dirstate changes since that time. This command does not alter
     the working directory.
 
     Transactions are used to encapsulate the effects of all commands
     that create new changesets or propagate existing changesets into a
     repository. For example, the following commands are transactional,
     and their effects can be rolled back:
 
     - commit
     - import
     - pull
     - push (with this repository as the destination)
     - unbundle
 
     This command is not intended for use on public repositories. Once
     changes are visible for pull by other users, rolling a transaction
     back locally is ineffective (someone else may already have pulled
     the changes). Furthermore, a race is possible with readers of the
     repository; for example an in-progress pull from the repository
     may fail if a rollback is performed.
 
     Returns 0 on success, 1 if no rollback data is available.
     """
     return repo.rollback(opts.get('dry_run'))
 
 def root(ui, repo):
     """print the root (top) of the current working directory
 
     Print the root directory of the current repository.
 
     Returns 0 on success.
     """
     ui.write(repo.root + "\n")
 
 def serve(ui, repo, **opts):
     """start stand-alone webserver
 
     Start a local HTTP repository browser and pull server. You can use
     this for ad-hoc sharing and browing of repositories. It is
     recommended to use a real web server to serve a repository for
     longer periods of time.
 
     Please note that the server does not implement access control.
     This means that, by default, anybody can read from the server and
     nobody can write to it by default. Set the ``web.allow_push``
     option to ``*`` to allow everybody to push to the server. You
     should use a real web server if you need to authenticate users.
 
     By default, the server logs accesses to stdout and errors to
     stderr. Use the -A/--accesslog and -E/--errorlog options to log to
     files.
 
     To have the server choose a free port number to listen on, specify
     a port number of 0; in this case, the server will print the port
     number it uses.
 
     Returns 0 on success.
     """
 
     if opts["stdio"]:
         if repo is None:
             raise error.RepoError(_("There is no Mercurial repository here"
                               " (.hg not found)"))
         s = sshserver.sshserver(ui, repo)
         s.serve_forever()
 
     # this way we can check if something was given in the command-line
     if opts.get('port'):
         opts['port'] = util.getport(opts.get('port'))
 
     baseui = repo and repo.baseui or ui
     optlist = ("name templates style address port prefix ipv6"
                " accesslog errorlog certificate encoding")
     for o in optlist.split():
         val = opts.get(o, '')
         if val in (None, ''): # should check against default options instead
             continue
         baseui.setconfig("web", o, val)
         if repo and repo.ui != baseui:
             repo.ui.setconfig("web", o, val)
 
     o = opts.get('web_conf') or opts.get('webdir_conf')
     if not o:
         if not repo:
             raise error.RepoError(_("There is no Mercurial repository"
                                     " here (.hg not found)"))
         o = repo.root
 
     app = hgweb.hgweb(o, baseui=ui)
 
     class service(object):
         def init(self):
             util.set_signal_handler()
             self.httpd = hgweb.server.create_server(ui, app)
 
             if opts['port'] and not ui.verbose:
                 return
 
             if self.httpd.prefix:
                 prefix = self.httpd.prefix.strip('/') + '/'
             else:
                 prefix = ''
 
             port = ':%d' % self.httpd.port
             if port == ':80':
                 port = ''
 
             bindaddr = self.httpd.addr
             if bindaddr == '0.0.0.0':
                 bindaddr = '*'
             elif ':' in bindaddr: # IPv6
                 bindaddr = '[%s]' % bindaddr
 
             fqaddr = self.httpd.fqaddr
             if ':' in fqaddr:
                 fqaddr = '[%s]' % fqaddr
             if opts['port']:
                 write = ui.status
             else:
                 write = ui.write
             write(_('listening at http://%s%s/%s (bound to %s:%d)\n') %
                   (fqaddr, port, prefix, bindaddr, self.httpd.port))
 
         def run(self):
             self.httpd.serve_forever()
 
     service = service()
 
     cmdutil.service(opts, initfn=service.init, runfn=service.run)
 
 def status(ui, repo, *pats, **opts):
     """show changed files in the working directory
 
     Show status of files in the repository. If names are given, only
     files that match are shown. Files that are clean or ignored or
     the source of a copy/move operation, are not listed unless
     -c/--clean, -i/--ignored, -C/--copies or -A/--all are given.
     Unless options described with "show only ..." are given, the
     options -mardu are used.
 
     Option -q/--quiet hides untracked (unknown and ignored) files
     unless explicitly requested with -u/--unknown or -i/--ignored.
 
     .. note::
        status may appear to disagree with diff if permissions have
        changed or a merge has occurred. The standard diff format does
        not report permission changes and diff only reports changes
        relative to one merge parent.
 
     If one revision is given, it is used as the base revision.
     If two revisions are given, the differences between them are
     shown. The --change option can also be used as a shortcut to list
     the changed files of a revision from its first parent.
 
     The codes used to show the status of files are::
 
       M = modified
       A = added
       R = removed
       C = clean
       ! = missing (deleted by non-hg command, but still tracked)
       ? = not tracked
       I = ignored
         = origin of the previous file listed as A (added)
 
     Returns 0 on success.
     """
 
     revs = opts.get('rev')
     change = opts.get('change')
 
     if revs and change:
         msg = _('cannot specify --rev and --change at the same time')
         raise util.Abort(msg)
     elif change:
         node2 = repo.lookup(change)
         node1 = repo[node2].parents()[0].node()
     else:
         node1, node2 = cmdutil.revpair(repo, revs)
 
     cwd = (pats and repo.getcwd()) or ''
     end = opts.get('print0') and '\0' or '\n'
     copy = {}
     states = 'modified added removed deleted unknown ignored clean'.split()
     show = [k for k in states if opts.get(k)]
     if opts.get('all'):
         show += ui.quiet and (states[:4] + ['clean']) or states
     if not show:
         show = ui.quiet and states[:4] or states[:5]
 
     stat = repo.status(node1, node2, cmdutil.match(repo, pats, opts),
                        'ignored' in show, 'clean' in show, 'unknown' in show,
                        opts.get('subrepos'))
     changestates = zip(states, 'MAR!?IC', stat)
 
     if (opts.get('all') or opts.get('copies')) and not opts.get('no_status'):
         ctxn = repo[nullid]
         ctx1 = repo[node1]
         ctx2 = repo[node2]
         added = stat[1]
         if node2 is None:
             added = stat[0] + stat[1] # merged?
 
         for k, v in copies.copies(repo, ctx1, ctx2, ctxn)[0].iteritems():
             if k in added:
                 copy[k] = v
             elif v in added:
                 copy[v] = k
 
     for state, char, files in changestates:
         if state in show:
             format = "%s %%s%s" % (char, end)
             if opts.get('no_status'):
                 format = "%%s%s" % end
 
             for f in files:
                 ui.write(format % repo.pathto(f, cwd),
                          label='status.' + state)
                 if f in copy:
                     ui.write('  %s%s' % (repo.pathto(copy[f], cwd), end),
                              label='status.copied')
 
 def summary(ui, repo, **opts):
     """summarize working directory state
 
     This generates a brief summary of the working directory state,
     including parents, branch, commit status, and available updates.
 
     With the --remote option, this will check the default paths for
     incoming and outgoing changes. This can be time-consuming.
 
     Returns 0 on success.
     """
 
     ctx = repo[None]
     parents = ctx.parents()
     pnode = parents[0].node()
 
     for p in parents:
         # label with log.changeset (instead of log.parent) since this
         # shows a working directory parent *changeset*:
         ui.write(_('parent: %d:%s ') % (p.rev(), str(p)),
                  label='log.changeset')
         ui.write(' '.join(p.tags()), label='log.tag')
         if p.rev() == -1:
             if not len(repo):
                 ui.write(_(' (empty repository)'))
             else:
                 ui.write(_(' (no revision checked out)'))
         ui.write('\n')
         if p.description():
             ui.status(' ' + p.description().splitlines()[0].strip() + '\n',
                       label='log.summary')
 
     branch = ctx.branch()
     bheads = repo.branchheads(branch)
     m = _('branch: %s\n') % branch
     if branch != 'default':
         ui.write(m, label='log.branch')
     else:
         ui.status(m, label='log.branch')
 
     st = list(repo.status(unknown=True))[:6]
 
     c = repo.dirstate.copies()
     copied, renamed = [], []
     for d, s in c.iteritems():
         if s in st[2]:
             st[2].remove(s)
             renamed.append(d)
         else:
             copied.append(d)
         if d in st[1]:
             st[1].remove(d)
     st.insert(3, renamed)
     st.insert(4, copied)
 
     ms = mergemod.mergestate(repo)
     st.append([f for f in ms if ms[f] == 'u'])
 
     subs = [s for s in ctx.substate if ctx.sub(s).dirty()]
     st.append(subs)
 
     labels = [ui.label(_('%d modified'), 'status.modified'),
               ui.label(_('%d added'), 'status.added'),
               ui.label(_('%d removed'), 'status.removed'),
               ui.label(_('%d renamed'), 'status.copied'),
               ui.label(_('%d copied'), 'status.copied'),
               ui.label(_('%d deleted'), 'status.deleted'),
               ui.label(_('%d unknown'), 'status.unknown'),
               ui.label(_('%d ignored'), 'status.ignored'),
               ui.label(_('%d unresolved'), 'resolve.unresolved'),
               ui.label(_('%d subrepos'), 'status.modified')]
     t = []
     for s, l in zip(st, labels):
         if s:
             t.append(l % len(s))
 
     t = ', '.join(t)
     cleanworkdir = False
 
     if len(parents) > 1:
         t += _(' (merge)')
     elif branch != parents[0].branch():
         t += _(' (new branch)')
     elif (parents[0].extra().get('close') and
           pnode in repo.branchheads(branch, closed=True)):
         t += _(' (head closed)')
     elif not (st[0] or st[1] or st[2] or st[3] or st[4] or st[9]):
         t += _(' (clean)')
         cleanworkdir = True
     elif pnode not in bheads:
         t += _(' (new branch head)')
 
     if cleanworkdir:
         ui.status(_('commit: %s\n') % t.strip())
     else:
         ui.write(_('commit: %s\n') % t.strip())
 
     # all ancestors of branch heads - all ancestors of parent = new csets
     new = [0] * len(repo)
     cl = repo.changelog
     for a in [cl.rev(n) for n in bheads]:
         new[a] = 1
     for a in cl.ancestors(*[cl.rev(n) for n in bheads]):
         new[a] = 1
     for a in [p.rev() for p in parents]:
         if a >= 0:
             new[a] = 0
     for a in cl.ancestors(*[p.rev() for p in parents]):
         new[a] = 0
     new = sum(new)
 
     if new == 0:
         ui.status(_('update: (current)\n'))
     elif pnode not in bheads:
         ui.write(_('update: %d new changesets (update)\n') % new)
     else:
         ui.write(_('update: %d new changesets, %d branch heads (merge)\n') %
                  (new, len(bheads)))
 
     if opts.get('remote'):
         t = []
         source, branches = hg.parseurl(ui.expandpath('default'))
         other = hg.repository(hg.remoteui(repo, {}), source)
         revs, checkout = hg.addbranchrevs(repo, other, branches, opts.get('rev'))
         ui.debug('comparing with %s\n' % url.hidepassword(source))
         repo.ui.pushbuffer()
         common, incoming, rheads = discovery.findcommonincoming(repo, other)
         repo.ui.popbuffer()
         if incoming:
             t.append(_('1 or more incoming'))
 
         dest, branches = hg.parseurl(ui.expandpath('default-push', 'default'))
         revs, checkout = hg.addbranchrevs(repo, repo, branches, None)
         other = hg.repository(hg.remoteui(repo, {}), dest)
         ui.debug('comparing with %s\n' % url.hidepassword(dest))
         repo.ui.pushbuffer()
         o = discovery.findoutgoing(repo, other)
         repo.ui.popbuffer()
         o = repo.changelog.nodesbetween(o, None)[0]
         if o:
             t.append(_('%d outgoing') % len(o))
 
         if t:
             ui.write(_('remote: %s\n') % (', '.join(t)))
         else:
             ui.status(_('remote: (synced)\n'))
 
 def tag(ui, repo, name1, *names, **opts):
     """add one or more tags for the current or given revision
 
     Name a particular revision using <name>.
 
     Tags are used to name particular revisions of the repository and are
     very useful to compare different revisions, to go back to significant
     earlier versions or to mark branch points as releases, etc.
 
     If no revision is given, the parent of the working directory is
     used, or tip if no revision is checked out.
 
     To facilitate version control, distribution, and merging of tags,
     they are stored as a file named ".hgtags" which is managed
     similarly to other project files and can be hand-edited if
     necessary. The file '.hg/localtags' is used for local tags (not
     shared among repositories).
 
     See :hg:`help dates` for a list of formats valid for -d/--date.
 
     Since tag names have priority over branch names during revision
     lookup, using an existing branch name as a tag name is discouraged.
 
     Returns 0 on success.
     """
 
     rev_ = "."
     names = [t.strip() for t in (name1,) + names]
     if len(names) != len(set(names)):
         raise util.Abort(_('tag names must be unique'))
     for n in names:
         if n in ['tip', '.', 'null']:
             raise util.Abort(_('the name \'%s\' is reserved') % n)
         if not n:
             raise util.Abort(_('tag names cannot consist entirely of whitespace'))
     if opts.get('rev') and opts.get('remove'):
         raise util.Abort(_("--rev and --remove are incompatible"))
     if opts.get('rev'):
         rev_ = opts['rev']
     message = opts.get('message')
     if opts.get('remove'):
         expectedtype = opts.get('local') and 'local' or 'global'
         for n in names:
             if not repo.tagtype(n):
                 raise util.Abort(_('tag \'%s\' does not exist') % n)
             if repo.tagtype(n) != expectedtype:
                 if expectedtype == 'global':
                     raise util.Abort(_('tag \'%s\' is not a global tag') % n)
                 else:
                     raise util.Abort(_('tag \'%s\' is not a local tag') % n)
         rev_ = nullid
         if not message:
             # we don't translate commit messages
             message = 'Removed tag %s' % ', '.join(names)
     elif not opts.get('force'):
         for n in names:
             if n in repo.tags():
                 raise util.Abort(_('tag \'%s\' already exists '
                                    '(use -f to force)') % n)
     if not rev_ and repo.dirstate.parents()[1] != nullid:
         raise util.Abort(_('uncommitted merge - please provide a '
                            'specific revision'))
     r = repo[rev_].node()
 
     if not message:
         # we don't translate commit messages
         message = ('Added tag %s for changeset %s' %
                    (', '.join(names), short(r)))
 
     date = opts.get('date')
     if date:
         date = util.parsedate(date)
 
     if opts.get('edit'):
         message = ui.edit(message, ui.username())
 
     repo.tag(names, r, message, opts.get('local'), opts.get('user'), date)
 
 def tags(ui, repo):
     """list repository tags
 
     This lists both regular and local tags. When the -v/--verbose
     switch is used, a third column "local" is printed for local tags.
 
     Returns 0 on success.
     """
 
     hexfunc = ui.debugflag and hex or short
     tagtype = ""
 
     for t, n in reversed(repo.tagslist()):
         if ui.quiet:
             ui.write("%s\n" % t)
             continue
 
         try:
             hn = hexfunc(n)
             r = "%5d:%s" % (repo.changelog.rev(n), hn)
         except error.LookupError:
             r = "    ?:%s" % hn
         else:
             spaces = " " * (30 - encoding.colwidth(t))
             if ui.verbose:
                 if repo.tagtype(t) == 'local':
                     tagtype = " local"
                 else:
                     tagtype = ""
             ui.write("%s%s %s%s\n" % (t, spaces, r, tagtype))
 
 def tip(ui, repo, **opts):
     """show the tip revision
 
     The tip revision (usually just called the tip) is the changeset
     most recently added to the repository (and therefore the most
     recently changed head).
 
     If you have just made a commit, that commit will be the tip. If
     you have just pulled changes from another repository, the tip of
     that repository becomes the current tip. The "tip" tag is special
     and cannot be renamed or assigned to a different changeset.
 
     Returns 0 on success.
     """
     displayer = cmdutil.show_changeset(ui, repo, opts)
     displayer.show(repo[len(repo) - 1])
     displayer.close()
 
 def unbundle(ui, repo, fname1, *fnames, **opts):
     """apply one or more changegroup files
 
     Apply one or more compressed changegroup files generated by the
     bundle command.
 
     Returns 0 on success, 1 if an update has unresolved files.
     """
     fnames = (fname1,) + fnames
 
     lock = repo.lock()
     try:
         for fname in fnames:
             f = url.open(ui, fname)
             gen = changegroup.readbundle(f, fname)
             modheads = repo.addchangegroup(gen, 'unbundle', 'bundle:' + fname,
                                            lock=lock)
     finally:
         lock.release()
 
     return postincoming(ui, repo, modheads, opts.get('update'), None)
 
 def update(ui, repo, node=None, rev=None, clean=False, date=None, check=False):
     """update working directory (or switch revisions)
 
     Update the repository's working directory to the specified
     changeset. If no changeset is specified, update to the tip of the
     current named branch.
 
     If the changeset is not a descendant of the working directory's
     parent, the update is aborted. With the -c/--check option, the
     working directory is checked for uncommitted changes; if none are
     found, the working directory is updated to the specified
     changeset.
 
     The following rules apply when the working directory contains
     uncommitted changes:
 
     1. If neither -c/--check nor -C/--clean is specified, and if
        the requested changeset is an ancestor or descendant of
        the working directory's parent, the uncommitted changes
        are merged into the requested changeset and the merged
        result is left uncommitted. If the requested changeset is
        not an ancestor or descendant (that is, it is on another
        branch), the update is aborted and the uncommitted changes
        are preserved.
 
     2. With the -c/--check option, the update is aborted and the
        uncommitted changes are preserved.
 
     3. With the -C/--clean option, uncommitted changes are discarded and
        the working directory is updated to the requested changeset.
 
     Use null as the changeset to remove the working directory (like
     :hg:`clone -U`).
 
     If you want to update just one file to an older changeset, use
     :hg:`revert`.
 
     See :hg:`help dates` for a list of formats valid for -d/--date.
 
     Returns 0 on success, 1 if there are unresolved files.
     """
     if rev and node:
         raise util.Abort(_("please specify just one revision"))
 
     if not rev:
         rev = node
 
     rev = cmdutil.revsingle(repo, rev, rev).rev()
 
     if check and clean:
         raise util.Abort(_("cannot specify both -c/--check and -C/--clean"))
 
     if check:
         # we could use dirty() but we can ignore merge and branch trivia
         c = repo[None]
         if c.modified() or c.added() or c.removed():
             raise util.Abort(_("uncommitted local changes"))
 
     if date:
         if rev:
             raise util.Abort(_("you can't specify a revision and a date"))
         rev = cmdutil.finddate(ui, repo, date)
 
     if clean or check:
         return hg.clean(repo, rev)
     else:
         return hg.update(repo, rev)
 
 def verify(ui, repo):
     """verify the integrity of the repository
 
     Verify the integrity of the current repository.
 
     This will perform an extensive check of the repository's
     integrity, validating the hashes and checksums of each entry in
     the changelog, manifest, and tracked files, as well as the
     integrity of their crosslinks and indices.
 
     Returns 0 on success, 1 if errors are encountered.
     """
     return hg.verify(repo)
 
 def version_(ui):
     """output version and copyright information"""
     ui.write(_("Mercurial Distributed SCM (version %s)\n")
              % util.version())
     ui.status(_(
         "\nCopyright (C) 2005-2010 Matt Mackall <[e-mail]> and others\n"
         "This is free software; see the source for copying conditions. "
         "There is NO\nwarranty; "
         "not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
     ))
 
 # Command options and aliases are listed here, alphabetically
 
 globalopts = [
     ('R', 'repository', '',
      _('repository root directory or name of overlay bundle file'),
      _('REPO')),
     ('', 'cwd', '',
      _('change working directory'), _('DIR')),
     ('y', 'noninteractive', None,
      _('do not prompt, assume \'yes\' for any required answers')),
     ('q', 'quiet', None, _('suppress output')),
     ('v', 'verbose', None, _('enable additional output')),
     ('', 'config', [],
      _('set/override config option (use \'section.name=value\')'),
      _('CONFIG')),
     ('', 'debug', None, _('enable debugging output')),
     ('', 'debugger', None, _('start debugger')),
     ('', 'encoding', encoding.encoding, _('set the charset encoding'),
      _('ENCODE')),
     ('', 'encodingmode', encoding.encodingmode,
      _('set the charset encoding mode'), _('MODE')),
     ('', 'traceback', None, _('always print a traceback on exception')),
     ('', 'time', None, _('time how long the command takes')),
     ('', 'profile', None, _('print command execution profile')),
     ('', 'version', None, _('output version information and exit')),
     ('h', 'help', None, _('display help and exit')),
 ]
 
 dryrunopts = [('n', 'dry-run', None,
                _('do not perform actions, just print output'))]
 
 remoteopts = [
     ('e', 'ssh', '',
      _('specify ssh command to use'), _('CMD')),
     ('', 'remotecmd', '',
      _('specify hg command to run on the remote side'), _('CMD')),
 ]
 
 walkopts = [
     ('I', 'include', [],
      _('include names matching the given patterns'), _('PATTERN')),
     ('X', 'exclude', [],
      _('exclude names matching the given patterns'), _('PATTERN')),
 ]
 
 commitopts = [
     ('m', 'message', '',
      _('use text as commit message'), _('TEXT')),
     ('l', 'logfile', '',
      _('read commit message from file'), _('FILE')),
 ]
 
 commitopts2 = [
     ('d', 'date', '',
      _('record datecode as commit date'), _('DATE')),
     ('u', 'user', '',
      _('record the specified user as committer'), _('USER')),
 ]
 
 templateopts = [
     ('', 'style', '',
      _('display using template map file'), _('STYLE')),
     ('', 'template', '',
      _('display with template'), _('TEMPLATE')),
 ]
 
 logopts = [
     ('p', 'patch', None, _('show patch')),
     ('g', 'git', None, _('use git extended diff format')),
     ('l', 'limit', '',
      _('limit number of changes displayed'), _('NUM')),
     ('M', 'no-merges', None, _('do not show merges')),
     ('', 'stat', None, _('output diffstat-style summary of changes')),
 ] + templateopts
 
 diffopts = [
     ('a', 'text', None, _('treat all files as text')),
     ('g', 'git', None, _('use git extended diff format')),
     ('', 'nodates', None, _('omit dates from diff headers'))
 ]
 
 diffopts2 = [
     ('p', 'show-function', None, _('show which function each change is in')),
     ('', 'reverse', None, _('produce a diff that undoes the changes')),
     ('w', 'ignore-all-space', None,
      _('ignore white space when comparing lines')),
     ('b', 'ignore-space-change', None,
      _('ignore changes in the amount of white space')),
     ('B', 'ignore-blank-lines', None,
      _('ignore changes whose lines are all blank')),
     ('U', 'unified', '',
      _('number of lines of context to show'), _('NUM')),
     ('', 'stat', None, _('output diffstat-style summary of changes')),
 ]
 
 similarityopts = [
     ('s', 'similarity', '',
      _('guess renamed files by similarity (0<=s<=100)'), _('SIMILARITY'))
 ]
 
 subrepoopts = [
     ('S', 'subrepos', None,
      _('recurse into subrepositories'))
 ]
 
 table = {
     "^add": (add, walkopts + subrepoopts + dryrunopts,
              _('[OPTION]... [FILE]...')),
     "addremove":
         (addremove, similarityopts + walkopts + dryrunopts,
          _('[OPTION]... [FILE]...')),
     "^annotate|blame":
         (annotate,
          [('r', 'rev', '',
            _('annotate the specified revision'), _('REV')),
           ('', 'follow', None,
            _('follow copies/renames and list the filename (DEPRECATED)')),
           ('', 'no-follow', None, _("don't follow copies and renames")),
           ('a', 'text', None, _('treat all files as text')),
           ('u', 'user', None, _('list the author (long with -v)')),
           ('f', 'file', None, _('list the filename')),
           ('d', 'date', None, _('list the date (short with -q)')),
           ('n', 'number', None, _('list the revision number (default)')),
           ('c', 'changeset', None, _('list the changeset')),
           ('l', 'line-number', None,
            _('show line number at the first appearance'))
          ] + walkopts,
          _('[-r REV] [-f] [-a] [-u] [-d] [-n] [-c] [-l] FILE...')),
     "archive":
         (archive,
          [('', 'no-decode', None, _('do not pass files through decoders')),
           ('p', 'prefix', '',
            _('directory prefix for files in archive'), _('PREFIX')),
           ('r', 'rev', '',
            _('revision to distribute'), _('REV')),
           ('t', 'type', '',
            _('type of distribution to create'), _('TYPE')),
          ] + subrepoopts + walkopts,
          _('[OPTION]... DEST')),
     "backout":
         (backout,
          [('', 'merge', None,
            _('merge with old dirstate parent after backout')),
           ('', 'parent', '',
            _('parent to choose when backing out merge'), _('REV')),
           ('r', 'rev', '',
            _('revision to backout'), _('REV')),
          ] + walkopts + commitopts + commitopts2,
          _('[OPTION]... [-r] REV')),
     "bisect":
         (bisect,
          [('r', 'reset', False, _('reset bisect state')),
           ('g', 'good', False, _('mark changeset good')),
           ('b', 'bad', False, _('mark changeset bad')),
           ('s', 'skip', False, _('skip testing changeset')),
           ('c', 'command', '',
            _('use command to check changeset state'), _('CMD')),
           ('U', 'noupdate', False, _('do not update to target'))],
          _("[-gbsr] [-U] [-c CMD] [REV]")),
     "branch":
         (branch,
          [('f', 'force', None,
            _('set branch name even if it shadows an existing branch')),
           ('C', 'clean', None, _('reset branch name to parent branch name'))],
          _('[-fC] [NAME]')),
     "branches":
         (branches,
          [('a', 'active', False,
            _('show only branches that have unmerged heads')),
           ('c', 'closed', False,
            _('show normal and closed branches'))],
          _('[-ac]')),
     "bundle":
         (bundle,
          [('f', 'force', None,
            _('run even when the destination is unrelated')),
           ('r', 'rev', [],
            _('a changeset intended to be added to the destination'),
            _('REV')),
           ('b', 'branch', [],
            _('a specific branch you would like to bundle'),
            _('BRANCH')),
           ('', 'base', [],
            _('a base changeset assumed to be available at the destination'),
            _('REV')),
           ('a', 'all', None, _('bundle all changesets in the repository')),
           ('t', 'type', 'bzip2',
            _('bundle compression type to use'), _('TYPE')),
          ] + remoteopts,
          _('[-f] [-t TYPE] [-a] [-r REV]... [--base REV]... FILE [DEST]')),
     "cat":
         (cat,
          [('o', 'output', '',
           _('print output to file with formatted name'), _('FORMAT')),
           ('r', 'rev', '',
            _('print the given revision'), _('REV')),
           ('', 'decode', None, _('apply any matching decode filter')),
          ] + walkopts,
          _('[OPTION]... FILE...')),
     "^clone":
         (clone,
          [('U', 'noupdate', None,
           _('the clone will include an empty working copy (only a repository)')),
           ('u', 'updaterev', '',
            _('revision, tag or branch to check out'), _('REV')),
           ('r', 'rev', [],
            _('include the specified changeset'), _('REV')),
           ('b', 'branch', [],
            _('clone only the specified branch'), _('BRANCH')),
           ('', 'pull', None, _('use pull protocol to copy metadata')),
           ('', 'uncompressed', None,
            _('use uncompressed transfer (fast over LAN)')),
          ] + remoteopts,
          _('[OPTION]... SOURCE [DEST]')),
     "^commit|ci":
         (commit,
          [('A', 'addremove', None,
            _('mark new/missing files as added/removed before committing')),
           ('', 'close-branch', None,
            _('mark a branch as closed, hiding it from the branch list')),
          ] + walkopts + commitopts + commitopts2,
          _('[OPTION]... [FILE]...')),
     "copy|cp":
         (copy,
          [('A', 'after', None, _('record a copy that has already occurred')),
           ('f', 'force', None,
            _('forcibly copy over an existing managed file')),
          ] + walkopts + dryrunopts,
          _('[OPTION]... [SOURCE]... DEST')),
     "debugancestor": (debugancestor, [], _('[INDEX] REV1 REV2')),
     "debugbuilddag":
         (debugbuilddag,
          [('m', 'mergeable-file', None, _('add single file mergeable changes')),
           ('a', 'appended-file', None, _('add single file all revs append to')),
           ('o', 'overwritten-file', None, _('add single file all revs overwrite')),
           ('n', 'new-file', None, _('add new file at each rev')),
          ],
          _('[OPTION]... TEXT')),
     "debugcheckstate": (debugcheckstate, [], ''),
     "debugcommands": (debugcommands, [], _('[COMMAND]')),
     "debugcomplete":
         (debugcomplete,
          [('o', 'options', None, _('show the command options'))],
          _('[-o] CMD')),
     "debugdag":
         (debugdag,
          [('t', 'tags', None, _('use tags as labels')),
           ('b', 'branches', None, _('annotate with branch names')),
           ('', 'dots', None, _('use dots for runs')),
           ('s', 'spaces', None, _('separate elements by spaces')),
          ],
          _('[OPTION]... [FILE [REV]...]')),
     "debugdate":
         (debugdate,
          [('e', 'extended', None, _('try extended date formats'))],
          _('[-e] DATE [RANGE]')),
     "debugdata": (debugdata, [], _('FILE REV')),
     "debugfsinfo": (debugfsinfo, [], _('[PATH]')),
     "debugindex": (debugindex, [], _('FILE')),
     "debugindexdot": (debugindexdot, [], _('FILE')),
     "debuginstall": (debuginstall, [], ''),
     "debugpushkey": (debugpushkey, [], _('REPO NAMESPACE [KEY OLD NEW]')),
     "debugrebuildstate":
         (debugrebuildstate,
          [('r', 'rev', '',
            _('revision to rebuild to'), _('REV'))],
          _('[-r REV] [REV]')),
     "debugrename":
         (debugrename,
          [('r', 'rev', '',
            _('revision to debug'), _('REV'))],
          _('[-r REV] FILE')),
     "debugrevspec":
         (debugrevspec, [], ('REVSPEC')),
     "debugsetparents":
         (debugsetparents, [], _('REV1 [REV2]')),
     "debugstate":
         (debugstate,
          [('', 'nodates', None, _('do not display the saved mtime'))],
          _('[OPTION]...')),
     "debugsub":
         (debugsub,
          [('r', 'rev', '',
            _('revision to check'), _('REV'))],
          _('[-r REV] [REV]')),
     "debugwalk": (debugwalk, walkopts, _('[OPTION]... [FILE]...')),
     "^diff":
         (diff,
          [('r', 'rev', [],
            _('revision'), _('REV')),
           ('c', 'change', '',
            _('change made by revision'), _('REV'))
          ] + diffopts + diffopts2 + walkopts + subrepoopts,
          _('[OPTION]... ([-c REV] | [-r REV1 [-r REV2]]) [FILE]...')),
     "^export":
         (export,
          [('o', 'output', '',
            _('print output to file with formatted name'), _('FORMAT')),
           ('', 'switch-parent', None, _('diff against the second parent')),
           ('r', 'rev', [],
            _('revisions to export'), _('REV')),
           ] + diffopts,
          _('[OPTION]... [-o OUTFILESPEC] REV...')),
     "^forget":
         (forget,
          [] + walkopts,
          _('[OPTION]... FILE...')),
     "grep":
         (grep,
          [('0', 'print0', None, _('end fields with NUL')),
           ('', 'all', None, _('print all revisions that match')),
           ('f', 'follow', None,
            _('follow changeset history,'
              ' or file history across copies and renames')),
           ('i', 'ignore-case', None, _('ignore case when matching')),
           ('l', 'files-with-matches', None,
            _('print only filenames and revisions that match')),
           ('n', 'line-number', None, _('print matching line numbers')),
           ('r', 'rev', [],
            _('only search files changed within revision range'), _('REV')),
           ('u', 'user', None, _('list the author (long with -v)')),
           ('d', 'date', None, _('list the date (short with -q)')),
          ] + walkopts,
          _('[OPTION]... PATTERN [FILE]...')),
     "heads":
         (heads,
          [('r', 'rev', '',
            _('show only heads which are descendants of STARTREV'),
            _('STARTREV')),
           ('t', 'topo', False, _('show topological heads only')),
           ('a', 'active', False,
            _('show active branchheads only (DEPRECATED)')),
           ('c', 'closed', False,
            _('show normal and closed branch heads')),
          ] + templateopts,
          _('[-ac] [-r STARTREV] [REV]...')),
     "help": (help_, [], _('[TOPIC]')),
     "identify|id":
         (identify,
          [('r', 'rev', '',
            _('identify the specified revision'), _('REV')),
           ('n', 'num', None, _('show local revision number')),
           ('i', 'id', None, _('show global revision id')),
           ('b', 'branch', None, _('show branch')),
           ('t', 'tags', None, _('show tags'))],
          _('[-nibt] [-r REV] [SOURCE]')),
     "import|patch":
         (import_,
          [('p', 'strip', 1,
            _('directory strip option for patch. This has the same '
              'meaning as the corresponding patch option'),
            _('NUM')),
           ('b', 'base', '',
            _('base path'), _('PATH')),
           ('f', 'force', None,
            _('skip check for outstanding uncommitted changes')),
           ('', 'no-commit', None,
            _("don't commit, just update the working directory")),
           ('', 'exact', None,
            _('apply patch to the nodes from which it was generated')),
           ('', 'import-branch', None,
            _('use any branch information in patch (implied by --exact)'))] +
          commitopts + commitopts2 + similarityopts,
          _('[OPTION]... PATCH...')),
     "incoming|in":
         (incoming,
          [('f', 'force', None,
            _('run even if remote repository is unrelated')),
           ('n', 'newest-first', None, _('show newest record first')),
           ('', 'bundle', '',
            _('file to store the bundles into'), _('FILE')),
           ('r', 'rev', [],
            _('a remote changeset intended to be added'), _('REV')),
           ('b', 'branch', [],
            _('a specific branch you would like to pull'), _('BRANCH')),
          ] + logopts + remoteopts + subrepoopts,
          _('[-p] [-n] [-M] [-f] [-r REV]...'
            ' [--bundle FILENAME] [SOURCE]')),
     "^init":
         (init,
          remoteopts,
          _('[-e CMD] [--remotecmd CMD] [DEST]')),
     "locate":
         (locate,
          [('r', 'rev', '',
            _('search the repository as it is in REV'), _('REV')),
           ('0', 'print0', None,
            _('end filenames with NUL, for use with xargs')),
           ('f', 'fullpath', None,
            _('print complete paths from the filesystem root')),
          ] + walkopts,
          _('[OPTION]... [PATTERN]...')),
     "^log|history":
         (log,
          [('f', 'follow', None,
            _('follow changeset history,'
              ' or file history across copies and renames')),
           ('', 'follow-first', None,
            _('only follow the first parent of merge changesets')),
           ('d', 'date', '',
            _('show revisions matching date spec'), _('DATE')),
           ('C', 'copies', None, _('show copied files')),
           ('k', 'keyword', [],
            _('do case-insensitive search for a given text'), _('TEXT')),
           ('r', 'rev', [],
            _('show the specified revision or range'), _('REV')),
           ('', 'removed', None, _('include revisions where files were removed')),
           ('m', 'only-merges', None, _('show only merges')),
           ('u', 'user', [],
            _('revisions committed by user'), _('USER')),
           ('', 'only-branch', [],
            _('show only changesets within the given named branch (DEPRECATED)'),
            _('BRANCH')),
           ('b', 'branch', [],
            _('show changesets within the given named branch'), _('BRANCH')),
           ('P', 'prune', [],
            _('do not display revision or any of its ancestors'), _('REV')),
          ] + logopts + walkopts,
          _('[OPTION]... [FILE]')),
     "manifest":
         (manifest,
          [('r', 'rev', '',
            _('revision to display'), _('REV'))],
          _('[-r REV]')),
     "^merge":
         (merge,
          [('f', 'force', None, _('force a merge with outstanding changes')),
           ('r', 'rev', '',
            _('revision to merge'), _('REV')),
           ('P', 'preview', None,
            _('review revisions to merge (no merge is performed)'))],
          _('[-P] [-f] [[-r] REV]')),
     "outgoing|out":
         (outgoing,
          [('f', 'force', None,
            _('run even when the destination is unrelated')),
           ('r', 'rev', [],
            _('a changeset intended to be included in the destination'),
            _('REV')),
           ('n', 'newest-first', None, _('show newest record first')),
           ('b', 'branch', [],
            _('a specific branch you would like to push'), _('BRANCH')),
          ] + logopts + remoteopts + subrepoopts,
          _('[-M] [-p] [-n] [-f] [-r REV]... [DEST]')),
     "parents":
         (parents,
          [('r', 'rev', '',
            _('show parents of the specified revision'), _('REV')),
          ] + templateopts,
          _('[-r REV] [FILE]')),
     "paths": (paths, [], _('[NAME]')),
     "^pull":
         (pull,
          [('u', 'update', None,
            _('update to new branch head if changesets were pulled')),
           ('f', 'force', None,
            _('run even when remote repository is unrelated')),
           ('r', 'rev', [],
            _('a remote changeset intended to be added'), _('REV')),
           ('b', 'branch', [],
            _('a specific branch you would like to pull'), _('BRANCH')),
          ] + remoteopts,
          _('[-u] [-f] [-r REV]... [-e CMD] [--remotecmd CMD] [SOURCE]')),
     "^push":
         (push,
          [('f', 'force', None, _('force push')),
           ('r', 'rev', [],
            _('a changeset intended to be included in the destination'),
            _('REV')),
           ('b', 'branch', [],
            _('a specific branch you would like to push'), _('BRANCH')),
           ('', 'new-branch', False, _('allow pushing a new branch')),
          ] + remoteopts,
          _('[-f] [-r REV]... [-e CMD] [--remotecmd CMD] [DEST]')),
     "recover": (recover, []),
     "^remove|rm":
         (remove,
          [('A', 'after', None, _('record delete for missing files')),
           ('f', 'force', None,
            _('remove (and delete) file even if added or modified')),
          ] + walkopts,
          _('[OPTION]... FILE...')),
     "rename|move|mv":
         (rename,
          [('A', 'after', None, _('record a rename that has already occurred')),
           ('f', 'force', None,
            _('forcibly copy over an existing managed file')),
          ] + walkopts + dryrunopts,
          _('[OPTION]... SOURCE... DEST')),
     "resolve":
         (resolve,
          [('a', 'all', None, _('select all unresolved files')),
           ('l', 'list', None, _('list state of files needing merge')),
           ('m', 'mark', None, _('mark files as resolved')),
           ('u', 'unmark', None, _('mark files as unresolved')),
           ('n', 'no-status', None, _('hide status prefix'))]
           + walkopts,
           _('[OPTION]... [FILE]...')),
     "revert":
         (revert,
          [('a', 'all', None, _('revert all changes when no arguments given')),
           ('d', 'date', '',
            _('tipmost revision matching date'), _('DATE')),
           ('r', 'rev', '',
            _('revert to the specified revision'), _('REV')),
           ('', 'no-backup', None, _('do not save backup copies of files')),
          ] + walkopts + dryrunopts,
          _('[OPTION]... [-r REV] [NAME]...')),
     "rollback": (rollback, dryrunopts),
     "root": (root, []),
     "^serve":
         (serve,
          [('A', 'accesslog', '',
            _('name of access log file to write to'), _('FILE')),
           ('d', 'daemon', None, _('run server in background')),
           ('', 'daemon-pipefds', '',
            _('used internally by daemon mode'), _('NUM')),
           ('E', 'errorlog', '',
            _('name of error log file to write to'), _('FILE')),
           # use string type, then we can check if something was passed
           ('p', 'port', '',
            _('port to listen on (default: 8000)'), _('PORT')),
           ('a', 'address', '',
            _('address to listen on (default: all interfaces)'), _('ADDR')),
           ('', 'prefix', '',
            _('prefix path to serve from (default: server root)'), _('PREFIX')),
           ('n', 'name', '',
            _('name to show in web pages (default: working directory)'),
            _('NAME')),
           ('', 'web-conf', '',
            _('name of the hgweb config file (see "hg help hgweb")'),
            _('FILE')),
           ('', 'webdir-conf', '',
            _('name of the hgweb config file (DEPRECATED)'), _('FILE')),
           ('', 'pid-file', '',
            _('name of file to write process ID to'), _('FILE')),
           ('', 'stdio', None, _('for remote clients')),
           ('t', 'templates', '',
            _('web templates to use'), _('TEMPLATE')),
           ('', 'style', '',
            _('template style to use'), _('STYLE')),
           ('6', 'ipv6', None, _('use IPv6 in addition to IPv4')),
           ('', 'certificate', '',
            _('SSL certificate file'), _('FILE'))],
          _('[OPTION]...')),
     "showconfig|debugconfig":
         (showconfig,
          [('u', 'untrusted', None, _('show untrusted configuration options'))],
          _('[-u] [NAME]...')),
     "^summary|sum":
         (summary,
          [('', 'remote', None, _('check for push and pull'))], '[--remote]'),
     "^status|st":
         (status,
          [('A', 'all', None, _('show status of all files')),
           ('m', 'modified', None, _('show only modified files')),
           ('a', 'added', None, _('show only added files')),
           ('r', 'removed', None, _('show only removed files')),
           ('d', 'deleted', None, _('show only deleted (but tracked) files')),
           ('c', 'clean', None, _('show only files without changes')),
           ('u', 'unknown', None, _('show only unknown (not tracked) files')),
           ('i', 'ignored', None, _('show only ignored files')),
           ('n', 'no-status', None, _('hide status prefix')),
           ('C', 'copies', None, _('show source of copied files')),
           ('0', 'print0', None,
            _('end filenames with NUL, for use with xargs')),
           ('', 'rev', [],
            _('show difference from revision'), _('REV')),
           ('', 'change', '',
            _('list the changed files of a revision'), _('REV')),
          ] + walkopts + subrepoopts,
          _('[OPTION]... [FILE]...')),
     "tag":
         (tag,
          [('f', 'force', None, _('replace existing tag')),
           ('l', 'local', None, _('make the tag local')),
           ('r', 'rev', '',
            _('revision to tag'), _('REV')),
           ('', 'remove', None, _('remove a tag')),
           # -l/--local is already there, commitopts cannot be used
           ('e', 'edit', None, _('edit commit message')),
           ('m', 'message', '',
            _('use <text> as commit message'), _('TEXT')),
          ] + commitopts2,
          _('[-f] [-l] [-m TEXT] [-d DATE] [-u USER] [-r REV] NAME...')),
     "tags": (tags, [], ''),
     "tip":
         (tip,
          [('p', 'patch', None, _('show patch')),
           ('g', 'git', None, _('use git extended diff format')),
          ] + templateopts,
          _('[-p] [-g]')),
     "unbundle":
         (unbundle,
          [('u', 'update', None,
            _('update to new branch head if changesets were unbundled'))],
          _('[-u] FILE...')),
     "^update|up|checkout|co":
         (update,
          [('C', 'clean', None, _('discard uncommitted changes (no backup)')),
           ('c', 'check', None,
            _('update across branches if no uncommitted changes')),
           ('d', 'date', '',
            _('tipmost revision matching date'), _('DATE')),
           ('r', 'rev', '',
            _('revision'), _('REV'))],
          _('[-c] [-C] [-d DATE] [[-r] REV]')),
     "verify": (verify, []),
     "version": (version_, []),
 }
 
 norepo = ("clone init version help debugcommands debugcomplete"
           " debugdate debuginstall debugfsinfo debugpushkey")
 optionalrepo = ("identify paths serve showconfig debugancestor debugdag"
                 " debugdata debugindex debugindexdot")

tests/test-backout.t

@@ -1,261 +1,289 b''
   $ HGMERGE=true; export HGMERGE
 
   $ hg init basic
   $ cd basic
 
 should complain
 
   $ hg backout
   abort: please specify a revision to backout
   [255]
   $ hg backout -r 0 0
   abort: please specify just one revision
   [255]
 
 basic operation
 
   $ echo a > a
   $ hg commit -d '0 0' -A -m a
   adding a
   $ echo b >> a
   $ hg commit -d '1 0' -m b
 
   $ hg backout -d '2 0' tip
   reverting a
   changeset 2:2929462c3dff backs out changeset 1:a820f4f40a57
   $ cat a
   a
 
 file that was removed is recreated
 
   $ cd ..
   $ hg init remove
   $ cd remove
 
   $ echo content > a
   $ hg commit -d '0 0' -A -m a
   adding a
 
   $ hg rm a
   $ hg commit -d '1 0' -m b
 
-  $ hg backout -d '2 0' --merge tip
+  $ hg backout -d '2 0' tip
   adding a
   changeset 2:de31bdc76c0d backs out changeset 1:76862dcce372
   $ cat a
   content
 
 backout of backout is as if nothing happened
 
   $ hg backout -d '3 0' --merge tip
   removing a
   changeset 3:7f6d0f120113 backs out changeset 2:de31bdc76c0d
   $ cat a 2>/dev/null || echo cat: a: No such file or directory
   cat: a: No such file or directory
 
 across branch
 
   $ cd ..
   $ hg init branch
   $ cd branch
   $ echo a > a
   $ hg ci -Am0
   adding a
   $ echo b > b
   $ hg ci -Am1
   adding b
   $ hg co -C 0
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
 
 should fail
 
   $ hg backout 1
   abort: cannot backout change on a different branch
   [255]
   $ echo c > c
   $ hg ci -Am2
   adding c
   created new head
 
 should fail
 
   $ hg backout 1
   abort: cannot backout change on a different branch
   [255]
 
 backout with merge
 
   $ cd ..
   $ hg init merge
   $ cd merge
 
   $ echo line 1 > a
   $ echo line 2 >> a
   $ hg commit -d '0 0' -A -m a
   adding a
 
 remove line 1
 
   $ echo line 2 > a
   $ hg commit -d '1 0' -m b
 
   $ echo line 3 >> a
   $ hg commit -d '2 0' -m c
 
   $ hg backout --merge -d '3 0' 1
   reverting a
   created new head
   changeset 3:26b8ccb9ad91 backs out changeset 1:5a50a024c182
   merging with changeset 3:26b8ccb9ad91
   merging a
   0 files updated, 1 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg commit -d '4 0' -m d
 
 check line 1 is back
 
   $ cat a
   line 1
   line 2
   line 3
 
 backout should not back out subsequent changesets
 
   $ hg init onecs
   $ cd onecs
   $ echo 1 > a
   $ hg commit -d '0 0' -A -m a
   adding a
   $ echo 2 >> a
   $ hg commit -d '1 0' -m b
   $ echo 1 > b
   $ hg commit -d '2 0' -A -m c
   adding b
+
+without --merge
   $ hg backout -d '3 0' 1
   reverting a
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg locate b
+  b
+  $ hg update -C tip
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg locate b
+  b
+
+with --merge
+  $ hg backout --merge -d '3 0' 1
+  reverting a
   created new head
   changeset 3:3202beb76721 backs out changeset 1:22bca4c721e5
-  the backout changeset is a new head - do not forget to merge
-  (use "backout --merge" if you want to auto-merge)
+  merging with changeset 3:3202beb76721
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  (branch merge, don't forget to commit)
   $ hg locate b
   b
   $ hg update -C tip
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg locate b
   [1]
 
   $ cd ..
   $ hg init m
   $ cd m
   $ echo a > a
   $ hg commit -d '0 0' -A -m a
   adding a
   $ echo b > b
   $ hg commit -d '1 0' -A -m b
   adding b
   $ echo c > c
   $ hg commit -d '2 0' -A -m b
   adding c
   $ hg update 1
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ echo d > d
   $ hg commit -d '3 0' -A -m c
   adding d
   created new head
   $ hg merge 2
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg commit -d '4 0' -A -m d
 
 backout of merge should fail
 
   $ hg backout 4
   abort: cannot backout a merge changeset without --parent
   [255]
 
 backout of merge with bad parent should fail
 
   $ hg backout --parent 0 4
   abort: cb9a9f314b8b is not a parent of b2f3bb92043e
   [255]
 
 backout of non-merge with parent should fail
 
   $ hg backout --parent 0 3
   abort: cannot use --parent on non-merge changeset
   [255]
 
 backout with valid parent should be ok
 
   $ hg backout -d '5 0' --parent 2 4
   removing d
   changeset 5:10e5328c8435 backs out changeset 4:b2f3bb92043e
 
   $ hg rollback
   rolling back to revision 4 (undo commit)
   $ hg update -C
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
   $ hg backout -d '6 0' --parent 3 4
   removing c
   changeset 5:033590168430 backs out changeset 4:b2f3bb92043e
 
   $ cd ..
 
 named branches
 
   $ hg init named_branches
   $ cd named_branches
 
   $ echo default > default
   $ hg ci -d '0 0' -Am default
   adding default
   $ hg branch branch1
   marked working directory as branch branch1
   $ echo branch1 > file1
   $ hg ci -d '1 0' -Am file1
   adding file1
   $ hg branch branch2
   marked working directory as branch branch2
   $ echo branch2 > file2
   $ hg ci -d '2 0' -Am file2
   adding file2
-  $ hg backout -d '3 0' -r 1 -m 'backout on branch1'
+
+without --merge
+  $ hg backout -r 1
+  removing file1
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg branch
+  branch2
+  $ hg status -A
+  R file1
+  C default
+  C file2
+
+with --merge
+  $ hg update -qC
+  $ hg backout --merge -d '3 0' -r 1 -m 'backout on branch1'
   removing file1
   created new head
   changeset 3:d4e8f6db59fb backs out changeset 1:bf1602f437f3
-  the backout changeset is a new head - do not forget to merge
-  (use "backout --merge" if you want to auto-merge)
-
-XXX maybe backout shouldn't suggest a merge here as it is a different branch?
+  merging with changeset 3:d4e8f6db59fb
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  (branch merge, don't forget to commit)
+  $ hg update -q -C 2
 
 on branch2 with branch1 not merged, so file1 should still exist:
 
   $ hg id
   45bbcd363bf0 (branch2)
   $ hg st -A
   C default
   C file1
   C file2
 
 on branch2 with branch1 merged, so file1 should be gone:
 
   $ hg merge
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -d '4 0' -m 'merge backout of branch1'
   $ hg id
   22149cdde76d (branch2) tip
   $ hg st -A
   C default
   C file2
 
 on branch1, so no file1 and file2:
 
   $ hg co -C branch1
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg id
   bf1602f437f3 (branch1)
   $ hg st -A
   C default
   C file1